Nickel / support - ternary eutectic salt catalyst, use thereof and methods of manufacture

Abstract

The present invention relates to novel catalyst materials including use thereof in catalytic transformations, such as in methods of producing syngas from mixtures of methane and carbon dioxide. The present invention further relates also to use of such novel catalysts in methods of improving operando life-time of a heterogenous catalyst comprising at least one active surface prone to carbon deposition and deactivation.

Description

[0001] NICKEL / SUPPORT - TERNARY EUTECTIC SALT CATALYST, USE THEREOF AND METHODS OF MANUFACTURE

[0002] Technical field

[0003] The present invention relates to novel catalyst materials including use thereof in catalytic transformations, such as in methods of producing syngas from mixtures of methane and carbon dioxide. The present invention further relates also to use of such novel catalysts in methods of improving operando life-time of a heterogenous catalyst comprising at least one active surface prone to carbon deposition and deactivation.

[0004] Background

[0005] The accumulation of carbon dioxide (CO2) in the Earth's atmosphere has reached alarming levels, leading to severe environmental consequences such as climate change and global warming. To address this pressing issue, there is an urgent need for innovative approaches that can effectively reduce CO2 emissions and mitigate its impact on the planet. Additionally, the utilization of CO2 plays a crucial role in carbon cycling for the advancement of the circular economy and has gathered significant research attention worldwide due to its potential to mitigate greenhouse gas emissions and contribute to sustainable development.

[0006] The simultaneous conversion of carbon dioxide and methane into valuable syngas is an attractive chemical conversion known in the field of heterogenous catalysis as dry reforming of methane or simply DRM. The feasibility of this reaction has attracted considerable attention in recent years for its prospective global warming mitigation, in no small part due to the appreciative conversion of two significant greenhouse gasses simultaneously into a mixture of CO and hydrogen with a ratio close to unity. The produced syngas offers great versatility e.g., as a feedstock in manufacturing of other high-value chemicals.

[0007] Despite these advantages and significant attention, the DRM is currently only of limited use for industrially relevant scale application.

[0008] Breaking C-H and O=C=O bonds as present in the substrate molecules require high activation energies and the reaction is indeed also highly endothermic (see reaction (1)). Therefore high supplies of energy in the form of external heating is needed to sustain the reaction for long periods of time to achieve sufficient conversion and product yields. CH4+ C02-> 2CO + 2H2AH298= 247.3 kj / mol (1)

[0009] To mitigate the unfavourable thermodynamics, catalysts are always implemented into the reactor setups intended for DRM, but this in turn makes DRM highly dependent on the specific catalyst used. Most investigated catalysts which demonstrate sufficient activity and selectivity for DRM reactions employ active phase metals from among the more expensive elements of the periodic table, such as Ru, Pd, Pt, Rh, Ir and Co, rendering the total costs too high for commercialization. The solution to the issue of cost has been to focus on Ni-based catalysts which are much cheaper than the above mentioned elements owing to it’s relatively abundant availability but nevertheless provide a sufficiently high bond scission activity.

[0010] Nickel unfortunately does not only catalyze DRM but also the formation of solid carbonaceous species depositions (known in the art as coke) from the break-down of methane (reactions (2) and (3) below). Such depositions poison the active catalyst surface rendering it virtually inactive and thereby over time as the number of active catalytic sites decreases, the total catalyst activity eventually falls below a thresholdvalue at which point the reactor must be shut down and the catalyst replaced with fresh material.

[0011] CH4C + 2H275 kj / mol (2)

[0012] 2CO C + CO2 -172.5 kj / mol (3)

[0013] The present invention aims to solve at least some of the above identified drawbacks associated not only with DRM, but related in general to catalyst poisoning by coke formations, such as provide novel catalyst materials and use of such novel catalysts in methods of improving in operando life-time of a heterogenous catalyst comprising at least one active surface prone to carbon deposition and deactivation.

[0014] Summary

[0015] Provided within the scope of the present invention is in a first aspect a method of improving in operando life-time of a heterogenous catalyst comprising a catalytically active metal having at least one catalytically active metal surface, wherein said metal surface is prone to catalysis deactivation by coke formation and / or coke deposition on said metal surface (i.e. reduction of catalytic activity over time as a result of coke), the method comprising at least partially coating said catalytically active metal surface with a eutectic metal salt composition, said eutectic metal salt composition comprising at least three different metal salt constituents, such as a ternary eutectic salt composition.

[0016] In a second major aspect of the present invention is provided a catalyst composition comprising: a. a porous solid support, b. at least one catalytically active metal, and c. a eutectic metal salt composition or a precursor thereof, said eutectic metal salt composition comprising at least three different metal salt constituents, such as in a ternary eutectic salt, further wherein said eutectic metal salt composition is present in an amount corresponding to from 0.1 to 20 % of the total available porous support pore volume and / or wherein said eutectic metal salt composition makes up 0.1 to 20 % by weight of the catalyst composition.

[0017] Additional aspects provided within the scope of the present invention also include methods of manufacture and use of such catalysts described hereabove in heterogenous catalysis, such as in dry reforming of methane to produce syngas.

[0018] Description of Drawings

[0019] Figure 1 :

[0020] Powder X-ray diffraction (PXRD) of catalysts evaluated in Example 1 herein. The support (Yttria-stabilized ZrC>2 - YSZ) is also presented for completeness. The tetragonal phase of YSZ is observed and most prone at 20 = 30°, 35°, 50°, and 60°. The Ni nanoparticles are barely visible at 20 = 37° and 43° due to the low concentration (position emphasized with a rectangular inset). The Ni peak locations correspond to NiO due to the oxidation of Ni° particles in the atmospheric air. PXRD recorded on a Malvern Panalytical Empyrean diffractometer equipped with a CuKa source in reflection mode.

[0021] Figure 2: catalytic testing of TEC-promoted catalysts in dry reforming of methane (DRM) compared to similar non-TEC-promoted catalysts. Reaction conditions: temperature: 350-750 °C (ramp rate 5 °C / min); pressure: 1 bar, GHSV: 54.000 ml / g h; CH4 / CO2 ratio: 1 :1; reactant composition 16 vol% CH4, 16 vol% CO2, 68 vol% N2.

[0022] The data shows that the TEC-promoted catalyst is only catalytically active at a later onset temperature than non-TEC-promoted catalysts. This could indicate that the TEC- promoter mixture has to melt before the incorporated Ni sites starts becoming catalytically active. Despite the higher onset temperature for DRM, the catalytic activity observed in the range 500-750 °C is very similar to the other tested catalysts.

[0023] Figure 3: catalytic testing of TEC-promoted catalysts in dry reforming of methane (DRM) compared to similar non-TEC-promoted catalysts. Reaction conditions: temperature: 700 °C; pressure: 1 bar, GHSV: 54.000 ml / g h; CH4 / CO2 ratio: 1 :1 ; reactant composition 16 vol% CH4, 16 vol% CO2, 68 vol% N2.

[0024] A) CH4 conversion as a function of time. Product gasses analyzed once per hour.

[0025] B) CO2 conversion as a function of time. Product gasses analyzed once per hour.

[0026] C) Evolution of product ratio between H2 / CO over 20 h. Product gasses analyzed once per hour.

[0027] The data shows that the TEC-promoted catalyst initially has a lower conversion of both methane (CH4) and carbon dioxide (CO2) conversion, however as the reaction time increases, the TEC-promoted catalyst deactivates significantly less compared to the non-TEC-promoted analogues, and at 16 h, the reactant conversion of 1% TEC / 5% Ni / YSZ is the highest of all tested catalysts.

[0028] Figure 4: Relative conversion of reactant gasses in TEC-promoted and non-TEC- promoted catalysts for first 50 hours of operation time for A) CH4 conversion, and B) CO2 conversion. Conversion was normalized to measured conversion at first data point (t = 1 h). Reaction conditions: temperature: 700 °C; pressure: 1 bar, GHSV: 54.000 ml / g h; CH4 / CO2 ratio: 1 :1; reactant composition 16 vol% CH4, 16 vol% CO2, 68 vol% N2.

[0029] The increased stability (as a result of less degradation and / or less coking) of the TEC- promoted catalyst becomes more pronounced as the reaction time is prolonged.

[0030] Figure 5: Reactant gasses conversion rates as a function of time for TEC-promoted catalysts comprising 1 wt% or 2 wt% TEC for A) CH4 conversion, and B) CO2 conversion. Reaction conditions: temperature: 700 °C; pressure: 1 bar, GHSV: 54.000 ml / g h; CH4 / CO2 ratio: 1 :1; reactant composition 16 vol% CH4, 16 vol% CO2, 68 vol% N2.

[0031] The results are mostly similar, however the higher loading 2 wt% TEC-promoted catalysts is slightly inferior in performance, although still better than non-TEC-promoted catalysts.

[0032] Figure 6: Panel showing post-operation temperature programmed oxidation (TPO) of the three catalysts 1% TEC / 5% Ni / YSZ (TEC-promoted, top panel), 1% K / 5% Ni / YSZ (non-TEC-promoted, middle panel) and 5% Ni / YSZ (non-TEC-promoted, bottom panel). Reaction conditions: 25-800 °C, 50 mL technical air / min, 1 bar. Here, technical air refers to a mixture of 79% nitrogen, 21% oxygen, no water, no carbon dioxide.

[0033] The data shows that the non-TEC-promoted catalysts comprise two different types of coke characterized by oxidation around 400 °C and 600 °C. Notably, the TEC- promoted catalyst (1% TEC / 5% Ni / YSZ, top panel) only comprise one kind of coke and in a significantly lower concentration. This is believed to directly related to the increased stability and life-time of the catalyst under operation conditions

[0034] Figure 7. Scanning electron microscopy (SEM) images depicting the surface morphology of:

[0035] A) freshly prepared TEC-promoted catalyst (1 wt.% TEC 15 wt.% Ni I YSZ);

[0036] B) spent TEC-promoted catalyst (1 wt.% TEC 15 wt.% Ni I YSZ) following catalytic reaction of at least 20 hours;

[0037] C) freshly prepared non-TEC-promoted catalyst (5 wt.% Ni I YSZ); and

[0038] D) spent non-TEC-promoted catalyst (5 wt.% Ni I YSZ) following the catalytic reaction of at least 20 hours.

[0039] Notably, carbon nanotubes or whisker-like structures are observed in the spent non- TEC-promoted catalyst (D), which are absent in both freshly prepared catalysts (A and C) and the spent TEC-promoted catalyst (B). This indicates significant coke deposition on the non-TEC-promoted catalyst during reaction, supporting the effectiveness of TEC promotion in mitigating carbon formation. Images acquired using a FEI Helios Nanolab 660 FIB-SEM with an Everhart-Thornley detector (see also Examples) Figure 8: catalytic testing of TEC Ni / AhCh (1 wt.% TEC / 5 wt.% Ni / AhCh) in dry reforming of methane (DRM) compared to non-TEC-promoted Ni / AhCh catalysts (5 wt.% Ni). Reaction conditions: temperature: 650 °C; pressure: 1 bar; CH4 / CO2 ratio: 1 :1 ; reactant composition 17 vol% CH4, 17 vol% CO2, 66 vol% N2.

[0040] A) CH4 conversion over 120 hours. Product gasses analyzed once per hour.

[0041] B) CO2 conversion over 120 hours. Product gasses analyzed once per hour.

[0042] The data shows that the TEC-promoted catalyst initially has a lower conversion of both methane (CH4) and carbon dioxide (CO2) conversion, however as the reaction time increases, the TEC-promoted catalyst deactivates significantly less or at a slower rate compared to the non-TEC-promoted analogues, After a period of approximately 70 h the Ni / AhCh catalyst begins to outperform non-TEC-promoted Ni / AhCh catalyst in both CCh and CH4 conversion rates, thereby supporting superiority of the TEC-promoted system for long-term operations such as industrial scale DRM which may exceed 1000 hours of continuous operation.

[0043] C) Relative CH4 conversion for TEC-promoted and non-TEC-promoted catalysts for first 120 hours of operation time, and

[0044] D) Relative CO2 conversion for TEC-promoted and non-TEC-promoted catalysts for first 120 hours of operation time.

[0045] Conversion was normalized to measured conversion at first data point (t = 1 h). Again, the increased stability (evidenced by the less / slower degradation and / or reduced coking) of the TEC-promoted catalyst becomes more pronounced as the reaction time is prolonged thereby supporting superiority of the TEC-promoted system for in particular long-term operations such as industrial scale DRM.

[0046] Figure 9: Catalytic testing of TEC_Ni / MgAI2O4(1 wt.% TEC I 5 wt.% Ni I MgAI2O4) in dry reforming of methane (DRM) compared to non-TEC-promoted Ni / MgAI2O4catalysts (5 wt.% Ni). Reaction conditions: temperature: 650 °C; pressure: 1 bar; CH4 / CO2ratio: 1 :1 ; reactant composition: 17 vol% CH4, 17 vol% CO2, 66 vol% N2.

[0047] A) CH4conversion over 120 hours. Product gases analyzed once per hour.

[0048] B) CO2conversion over 120 hours. Product gases analyzed once per hour.

[0049] The data show that while the TEC-promoted catalyst exhibits slightly lower initial conversion of both methane (CH4) and carbon dioxide (CO2), the long-term performance is generally comparable to the non-TEC-promoted analogue. Though no distinct improvement in conversion is observed, the TEC-promoted system maintains stable activity over time, suggesting potential benefits under certain operating conditions.

[0050] C) Relative CH4conversion of reactant gases in TEC-promoted and non-TEC- promoted catalysts for first 120 hours of operation.

[0051] D) Relative CO2 conversion of reactant gases in TEC-promoted and non-TEC- promoted catalysts for first 120 hours of operation.

[0052] Conversion was normalized to measured conversion at first data point (t = 1 h).

[0053] The increased stability of the TEC-promoted catalyst becomes more apparent over extended reaction time. While a clear enhancement in conversion is not observed in this data set, other experimental results suggest reduced coke formation with TEC promotion, supporting its potential role in improving catalyst durability.

[0054] Figure 10: Temperature programmed oxidation (TPO) of the catalysts TEC_Ni / MgAl2C>4 (1 wt.% TEC 15 wt.% Ni I MgAhOt) and the non-TEC-promoted Ni / MgAhO4 (5 wt.% Ni I MgAhOt) after 120 h of reaction time. Reaction conditions: 25- 800 °C, 50 mL technical air / min, 1 bar. Here, technical air refers to a mixture of 79% nitrogen, 21% oxygen, no water, no carbon dioxide.

[0055] The data shows that the non-TEC-promoted catalysts comprise a significantly higher concentration of coke deposits characterized by oxidation predominantly between 550 °C and 700 °C compared to the TEC-promoted catalyst (1 wt.% TEC 15 wt.% Ni I MgAhOt). This is believed to directly related to the increased activity and life-time of the catalyst under operation conditions observed in Figure 9.

[0056] Detailed description

[0057] The invention is defined by the claims.

[0058] The present invention provides catalysts and methods related to heterogenous catalysis, with special emphasis on reactions involving carbon dioxide such as the dry reforming of methane (DRM) into syngas. Syngas or sometimes “synthesis gas” is a gaseous mixture of hydrogen and carbon dioxide, highly sought after as a feedstock in the chemical production due to is versatile use. The catalysts and methods described herein are designed to provide an enhanced efficiency and stability and by association reduced cost of operation associated with conventional DRM methods. In particular carbon deposition and / or formation, known as ‘coking’ in the field poses a challenge. The present inventors have surprisingly identified a methodology for generating catalysts which are less prone to suffer the challenges of coking, thereby providing a longer operation lifetime before critical plant shutdown and catalyst replacing is needed. The challenges of coking in heterogenous catalysis are well-known. Catalyst deactivation as a result of coke is often associated with clogging and / or blocking of pores in the support or active sites of the catalyst and / or support. As a result, the total number of available active sites for the catalyst decreases which can be evidenced by a reduced catalytic activity. Coking may be exemplified in the form of amorphous carbonaceous deposits or in the form of carbon nanotubes, also referred to in the art as carbon ‘whiskers’. Figure 7 provides an exemplary SEM image of a spent conventional YSZ catalyst (i.e. which was not at least partially coated with a eutectic metal salt as the catalysts of the invention), where coke whiskers can be readily identified in numerous amounts. Thus, as used herein, the term “prone to coking” refers to a catalyst system which is composed of a porous support and an active metal catalyst. Preferably, the catalyst is a transition-metal catalyst, more preferably Ni, Co, Fe, Ru, Rh, Cu, Co, or a binary or ternary mixture thereof. Preferably, the porous support is a porous oxide support, preferably MgAhOt, ZrC>2, CeC>2, AI2O3, TiC>2, SiC>2, CaO, K2O, BaO, SrTiCh, La2O3, MgO, CaTiCh, BaTiCh and zeolites such as GME, FAU, ANA, MOR, HEU, LTA, and MFI zeolite types.

[0059] Most notably, the simplistic methodology involves partially coating, in principle any heterogenous catalyst composition having an exposed metal surface prone to coke formation, with a composition able to catalyze the reverse Bouduard reaction. Exemplified herein, eutectic metal salt compositions are used for this purpose as they can provide a large range of operation temperatures by varying the metal ratio composition which influences the thermal melting temperature of the eutectic.

[0060] As used herein, the term “eutectic” as used in relation to eutectic metal salt compositions is to be construed as referring to a homogeneous mixture of two or more metal salts that, when combined, form a composition with a characteristic melting behavior distinct from that of its individual components. A ternary eutectic salt composition refers to a homogenous mixture of three metal salts, preferably wherein the metals are Li, Na, and K, more preferably wherein the metal salts are carbonates of Li, Na, and K (denoted herein as TEC). Ternary eutectic carbonate (TEC) compositions may exemplary be obtained by heating / firing / calcination of a different ternary eutectic metal salt (a precursor) in an atmosphere of carbon dioxide in order to prevent formation of the oxide. Such precursors may be based on at temperatures above is one example of a metal salt eutectic

[0061] The inventors of the present application has prepared multiple catalyst systems and tested using different porous supports and precursor chemistries known to those skilled in the field of heterogenous catalysis to demonstrate a general working concept of the developed ternary eutectic carbonate (TEC) coating methodology. The concept is proven reproducible across the different oxide-based supports evaluated which include yttria-stabilized zirconia (YSZ), aluminum oxide (AI2O3) and magnesium aluminum oxide (MgAhCL) supports. These examples demonstrate flexibility of the novel catalyst design, which unequivocally results in reduced coke depositions and improved operation performance for the catalysts coated with the TEC composition, supporting the general applicability to various catalyst-support combinations and catalytic reactions.

[0062] The following sections provides a more detailed description of the present invention including variations and alternatives and serves to illustrate the broad applicability of the disclosure.

[0063] One embodiment of the present disclosure is to provide a catalyst composition comprising: a. a porous solid support, b. at least one catalytically active metal, and c. a eutectic metal salt composition or a precursor thereof, said eutectic metal salt composition comprising at least three different metal salt constituents, such as in a ternary eutectic salt, further wherein said eutectic metal salt composition is present in an amount corresponding to from 0.1 to 20 % of the total available porous support pore volume and / or wherein said eutectic metal salt composition makes up 0.1 to 20 % by weight of the catalyst composition. One embodiment of the present disclosure is to provide a catalyst composition comprising: a. a porous solid support, b. at least one catalytically active metal, and c. a eutectic metal salt composition or a precursor thereof, said eutectic metal salt composition comprising at least three different metal salt constituents, such as in a ternary eutectic salt, further wherein said eutectic metal salt composition is present in an amount corresponding to from 0.1 to 20 % of the total available porous support pore volume.

[0064] One embodiment of the present disclosure is to provide a catalyst composition comprising: a. a porous solid support, b. at least one catalytically active metal, and c. a eutectic metal salt composition or a precursor thereof, said eutectic metal salt composition comprising at least three different metal salt constituents, such as in a ternary eutectic salt, further wherein said eutectic metal salt composition makes up 0.1 to 20 % by weight of the catalyst composition.

[0065] In one preferred embodiment of the present disclosure, the eutectic metal salt composition makes up 0.1 to 20 % by weight of the catalyst composition.

[0066] Porous solid supports are a type of materials well known to those in the art, and especially those within heterogenous catalysis where conventional solid porous supports include metal oxides, metal nitrides, metal carbonates and metal chlorides, but may also contain carbon-based supports such as graphite supports. Most well- known examples are oxides of aluminum (Al) and / or silicon (Si), such as aluminumsilicates (zeolites), but also exemplary binary metal oxides such as ZrC>2, CeC>2, AI2O3, TiC>2, SiC>2, CaO, and K2O are frequently used.

[0067] Conventionally, porous solid supports have also sometimes been referred to as ceramic supports because these materials may often times be produced via a step of calcination at a high temperature, to provide a heat- and / or corrosion-resistant material. As opposed to dense solid supports, porous solid supports have the advantage and unique property of being filled with a plurality of pores, cavities, channels or interstices, which may all be of varying size and frequency. Pore size may therefore be according to IIIPAC classifications (IUPAC Compendium of Chemical Terminology, 5thed. 2025) given as either of micropores, mesopores, or macropores. It will be readily understood by those in the art that a solid porous support may comprise one or more of micro-, meso-, or macropores as part of the porous support structure. In such case, classification of pore type may be based on the average pore size of the solid. The IIIPAC definitions are given as: micropores - having pore size with diameters not exceeding 2 nm; mesopores - having pore size with diameters between 2 nm and 50 nm; macropores - having pore size with diameters exceeding 50 nm.

[0068] Porous supports are particularly useful in heterogeneous catalysis because the nature of being porous allows gaseous compounds to flow through the channels and pores of the solid support, which in turn are often decorated with active sites for facilitating catalytic reactions at the gas-solid interface. The active sites may be in the form of either of acidic vacancies of the support, or exposed metal surfaces which have been decorated on the support by impregnation or chemical modification with a metal substrate. The term “porous solid support” as used herein may therefore to a porous solid as described above and having one or more of micro-, meso-, and macropores, optionally wherein the porous support has a surface area of 50 to 250 m2 / g, optionally wherein the surface area is determined by Brunauer-Emmett-Teller (BET) analysis.

[0069] The catalyst composition described within the present disclosure comprise at least one catalytically active metal (the catalyst). The term should be construed as referring to a transition metal (transition metal referring to metals of the d-block of the periodic table of elements) that participates in a specific chemical reaction in which the metal facilitates, or enables, the chemical reaction to proceed differently than otherwise possible without the metal undergoing permanent chemical change itself. The term “catalytically active metal” as used herein may therefor also be used interchangeably with “transition metal”. Furthermore, a catalytically active metal according to the present disclosure and as well-known in relation to heterogenous catalysis is characterized by comprising at least one catalytically active metal surface, which refers to the solid surface of the catalytically active metal (the catalyst) on which the catalytic reaction takes places - the active site. The catalytically active surface of the catalytically active metal (i.e. the catalyst surface) may also be characterized on the microscopic level by the presence of surface morphologies known as kinks, steps, terraces, facets or crystal lattice planes referred to by their respective {hkl} Miller indices. Often these morphologies are associated with certain preferred Miller indices which may take the form of exemplary {111}, {221}, {321}. All functional metal catalysts have at least one catalytically active metal surface, which represents the active site for a gas molecule to be associated during heterogenous catalysis.

[0070] In one embodiment of the present disclosure, said eutectic metal salt composition is selected from ternary eutectic carbonate, ternary eutectic hydroxide, ternary eutectic nitrate and ternary eutectic chloride, or a mixture thereof.

[0071] In one embodiment of the present disclosure, said catalyst composition comprising: a. a porous solid support, b. at least one catalytically active metal, and c. a eutectic metal salt composition or a precursor thereof, said eutectic metal salt composition comprising at least a ternary eutectic salt, optionally wherein said ternary eutectic salt is selected from carbonate, formate, hydroxide, nitrate and chloride, or a mixture thereof, further wherein said eutectic metal salt composition is present in an amount corresponding to from 0.1 to 20 % of the total available porous support pore volume.

[0072] In one embodiment of the present disclosure, said catalyst composition comprising: a. a porous solid support, b. at least one catalytically active metal, and c. a eutectic metal salt composition or a precursor thereof, said eutectic metal salt composition comprising at least a ternary eutectic salt, optionally wherein said ternary eutectic salt is selected from carbonate, formate, hydroxide, nitrate and chloride, or a mixture thereof, further wherein said eutectic metal salt composition makes up 0.1 to 20 % by weight of the catalyst composition.

[0073] In one embodiment of the present disclosure, said eutectic metal salt composition comprises more than three different metal salt constituents, such as may comprise any one of ternary eutectic carbonate, ternary eutectic hydroxide, ternary eutectic nitrate and ternary eutectic chloride, or a mixture thereof, and further comprising one or more additional and / or second metal salt, such as wherein the one or more additional and / or second metal salt is selected from the group consisting of alkali metal salt, earth-alkali metal salt, p-block metal salt, d-block metal salt and f-block metal salt.

[0074] As used herein the term “p-block metal salt” refers to salts of metal ions located in the p-block of the periodic table of elements. Elements confined to the p-block are known to those in the art and comprise the (metal) elements with atomic number 5, 13-14, 31 - 33, 49-52, and 81-83.

[0075] As used herein the term “d-block metal salt” refers to salts of metal ions located in the d-block of the periodic table of elements. Elements confined to the d-block are known to those in the art and comprise the elements with atomic number 21-30, 39-48 and 72- 80. For emphasis, the lanthanides and actinides are not considered d-block metals within the meaning of the present disclosure (see f-block metal salt).

[0076] As used herein, the term “f-block metal salt” refers to salts of metal ions located in the f-block of the periodic table of elements. Elements confined to the f-block are known to those in the art and comprise the elements with atomic number 57-71 and 89-103.

[0077] In one embodiment of the present disclosure, the one or more additional and / or second metal salt is selected from the group consisting of alkali metal salt and earth-alkali metal salt, such as Li, Na, K, Rb, Cs, Mg, Ca, Sr or Ba.

[0078] In one embodiment of the present disclosure, the catalyst is a catalyst composite, such as a composite comprising a porous solid support featuring at least one catalytically active metal impregnated and / or incorporated into said solid support, further being at least partially coated with said eutectic metal salt composition. Within the present disclosure, the term “partially coated” is to be interpreted as not referring to completely coated, such as there are areas of catalytically active metal which is not coated with said eutectic metal salt composition.

[0079] In one embodiment of the present disclosure, the ternary eutectic salt is ternary eutectic carbonate or a ternary eutectic salt composition suitable for being transformed into the corresponding carbonate upon exposure to gaseous carbon dioxide, such as ternary eutectic formate, ternary eutectic hydroxide, ternary eutectic nitrate and ternary eutectic chloride, or a mixture thereof.

[0080] In one embodiment of the present disclosure, the eutectic metal salt composition comprise or consist of a ternary eutectic salt composition, such as preferably comprise or consist of ternary eutectic carbonate (TEC).

[0081] In one embodiment of the present disclosure, said eutectic metal salt composition comprise an alkali metal ternary eutectic or alkaline earth metal ternary eutectic, or mixture thereof.

[0082] In one embodiment of the present disclosure, the eutectic metal salt composition comprise or consist of a ternary eutectic alkali metal salt composition, such as preferably comprise or consist of ternary eutectic alkali metal carbonate.

[0083] In one embodiment of the present disclosure, said eutectic metal salt composition comprise salts of Li, Na and K in an amount corresponding to 1 :1 :1 by weight of the eutectic metal salt composition. The salt may preferably be selected from carbonate, formate, nitrate, chloride and hydroxide.

[0084] In one embodiment of the present disclosure, said eutectic metal salt composition comprise at least three carbonate salts individually selected from U2CO3, Na2COs, K2CO3, Rb2CO3, CS2CO3, MgCOs, CaCCh, SrCCh, and BaCCh.

[0085] In one embodiment of the present disclosure, said eutectic metal salt composition comprise an alkali metal ternary eutectic carbonate.

[0086] In one embodiment of the present disclosure, said eutectic metal salt composition comprise three distinct alkali metal salts selected from U2CO3, Na2COs, K2CO3, Rb2CO3, CS2CO3.

[0087] In one embodiment of the present disclosure, the ternary eutectic salt is ternary eutectic formate. In one embodiment of the present disclosure, the ternary eutectic formate comprises at least three formate salts individually selected from Li(C>2CH), Na(C>2CH), K(C>2CH), Rb(O2CH), CS(O2CH), Mg(O2CH)2, Ca(O2CH)2, Sr(O2CH)2, and Ba(O2CH)2, or a hydrate thereof.

[0088] In one embodiment of the present disclosure, the ternary eutectic salt is ternary eutectic hydroxide.

[0089] In one embodiment of the present disclosure, the ternary eutectic hydroxide comprises at least three hydroxide salts individually selected from LiOH, NaOH, KOH, RbOH, CsOH, Mg(OH)2, Ca(OH)2, Sr(OH)2, and Ba(OH)2, or a hydrate thereof.

[0090] In one embodiment of the present disclosure, the ternary eutectic salt is ternary eutectic nitrate.

[0091] In one embodiment of the present disclosure, the ternary eutectic nitrate comprises at least three nitrate salts individually selected from LiNOs, NaNCh, KNO3, RbNOs, CsNOs, Mg(NO3)2, Ca(NO2)2, Sr(NOs)2, and Ba(NO2)2, or a hydrate thereof.

[0092] In one embodiment of the present disclosure, the ternary eutectic salt is ternary eutectic chloride.

[0093] In one embodiment of the present disclosure, the ternary eutectic chloride comprises at least three chloride salts individually selected from LiCI, NaCI, KCI, RbCI, CsCI, MgCh, CaCh, SrCh, and BaCh, or a hydrate thereof.

[0094] In one embodiment of the present disclosure, the ternary eutectic salt is an alkali metal ternary eutectic salt, such as alkali metal ternary carbonate, formate, nitrate, hydroxide, or chloride.

[0095] In one embodiment of the present disclosure, said eutectic metal salt composition comprise U2CO3, Na2COs and K2CO3. In one embodiment of the present disclosure, said eutectic metal salt composition comprise U2CO3, Na2COs and K2CO3 in an amount corresponding to 1 :1 :1 by weight of the eutectic composition.

[0096] In one embodiment of the present disclosure, said eutectic metal salt composition comprise 33 (±2) wt% U2CO3; 33 (±2) wt% K2CO3; 33 (±2) wt% Na2COs by weight of the eutectic composition.

[0097] In one embodiment of the present disclosure, said eutectic metal salt composition comprise 32.1 (±1.5) wt% U2CO3; 34.5 (±1.5) wt% K2CO3; 33.4 (±1.5) wt% Na2COs by weight of the eutectic composition.

[0098] In one embodiment of the present disclosure, said eutectic metal salt composition comprise 32.1 (±1.0) wt% U2CO3; 34.5 (±1.0) wt% K2CO3; 33.4 (±1.0) wt% Na2COs by weight of the eutectic composition.

[0099] In one embodiment of the present disclosure, said eutectic metal salt composition comprise 32.1 (±0.5) wt% U2CO3; 34.5 (±0.5) wt% K2CO3; 33.4 (±0.5) wt% Na2COs by weight of the eutectic composition.

[0100] In one embodiment of the present disclosure, said eutectic metal salt composition comprise U2CO3 : K2CO3 : Na2COs in a molar ratio of 43.5 : 25 : 31.5

[0101] In one embodiment of the present disclosure, said eutectic metal salt composition is characterized by a melting point in the range of 390 °C to 750 °C, such as 390 °C to 400 °C, such as 400 °C to 450 °C, such as 450 °C to 500 °C, such as 500 °C to 550 °C, such as 550 °C to 600 °C, such as 600 °C to 650 °C, such as 650 °C to 700 °C, such as 700 °C to 750 °C.

[0102] In one embodiment of the present disclosure, said eutectic metal salt composition is characterized by a melting point of at least 390 °C, such as of at least 450 °C, such as of at least 500 °C, such as of at least 550 °C, such as of at least 600 °C, such as of at least 650 °C, such as of at least 700 °C. In one embodiment of the present disclosure, said eutectic metal salt composition is characterized by a melting point in the range of 397 °C to 410 °C.

[0103] In one embodiment of the present disclosure, the ternary eutectic salt is present in an amount corresponding to from 0.1 to 20 wt% of the total catalyst weight, such as from 0.1 to 1 .0 wt%, such as from 1.0 to 2.0 wt%, such as from 2.0 to 3.0 wt%, such as from 3.0 to 4.0 wt%, such as from 4.0 to 5.0 wt%, such as from 5.0 to 7.0 wt%, such as from 7.0 to 10 wt%, such as from 10 wt% to 20 wt%.

[0104] In one embodiment of the present disclosure, the ternary eutectic salt is present in an amount corresponding to from 0.5 to 5 wt% of the total catalyst weight, such as 0.5 wt%, 1 .0 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%, 3.0 wt%, 3.5 wt%, 4.0 wt%, 4.5 wt% or 5.0 wt%.

[0105] In one embodiment of the present disclosure, the ternary eutectic salt is present in an amount corresponding to from 0.1 to 20 % of the total available porous support pore volume, such as from 0.1 to 1.0 %, such as from 1.0 to 2.0 %, such as from 2.0 to 3.0 %, such as from 3.0 to 4.0 %, such as from 4.0 to 5.0 %, such as from 5.0 to 7.0 %, such as from 7.0 to 10 %, such as from 10 % to 20 %.

[0106] In one embodiment of the present disclosure, the ternary eutectic salt is present in an amount corresponding to from 0.5 to 5 % of the total available porous support pore volume, such as 0.5 %, 1.0 %, 1.5 %, 2.0 %, 2.5 %, 3.0 %, 3.5 %, 4.0 %, 4.5 % or 5.0 %.

[0107] Solid support

[0108] In one embodiment of the present disclosure, said porous solid support is a ceramic support, such as a metal oxide and / or a nitride and / or a carbonate and / or a chloride and / or a mixture thereof.

[0109] In one embodiment of the present disclosure, said ceramic support is selected from ZrO2, CeO2, AI2O3, TiO2, SiO2, CaO, K2O, MgCh, SiaN4, MgAhO4, BaO, SrTiOa, La2Os, MgO, CaTiOs, BaTiCh and zeolites such as GME, FAU, ANA, MOR, HEU, LTA, and MFI zeolite types, and mixtures thereof. As used herein, the three-letter nomenclature (e.g., GME) refers to three-letter zeolite structure identifiers as used and known to those skilled in the art. GME is exemplary well-used nomenclature for the zeolite gmelinite. Additional technical detail on specific zeolite frameworks may be found in the online database of zeolite structures available at https: / / www.iza- structure.org / databases / and incorporated by reference in its entirety herein.

[0110] In one embodiment of the present disclosure, said ceramic support is selected from MgAI2O4, ZrC>2, CeC>2, AI2O3, TiC>2, SiC>2, CaO, K2O, BaO, SrTiCh, La2O3, MgO, CaTiCh, BaTiOs and mixtures thereof.

[0111] In one embodiment of the present disclosure, said ceramic support is a zeolite-type framework selected from the group consisting of GME, FAU, ANA, MOR, HEU, LTA, MFI and mixtures thereof.

[0112] In one embodiment of the present disclosure, said ceramic support is selected from ZrO2, CeO2, AI2O3, MgAhO4 and mixtures thereof.

[0113] In one preferred embodiment of the present disclosure, said ceramic support is MgAhO4, also sometimes simply referred to in the art as spinel.

[0114] In one preferred embodiment of the present disclosure, said ceramic support is AI2O3, also sometimes simply referred to in the art as alumina or aluminum oxide.

[0115] In one preferred embodiment of the present disclosure, said ceramic support is ZrO2, also sometimes simply referred to in the art as zirconia. The zirconia may within the context of the present disclosure also refer to yttrium-stabilized zirconia (or YSZ) which is common and known to those in the art.

[0116] In one preferred embodiment of the present disclosure, said ceramic support is CeO2, also sometimes simply referred to in the art as ceria.

[0117] In one embodiment of the present disclosure, said ceramic support further comprises at least one doping ion and / or metal, optionally wherein said doping ion and / or metal increases the thermal stability of the support. In one embodiment of the present disclosure, said ceramic support further comprises at least one doping ion and / or metal, optionally wherein said doping ion and / or metal which increases the number of oxygen vacancies in the support.

[0118] In one embodiment of the present disclosure, the at least one doping ion and / or metal is yttrium, lanthanum, silicon, magnesium, calcium.

[0119] In one embodiment of the present disclosure, the at least one doping ion and / or metal is yttrium.

[0120] Surface area and pore volume

[0121] In one embodiment of the present disclosure, the catalyst support (porous solid support) has a surface area of 50 to 250 m2 / g as determined by Brunauer-Emmett- Teller (BET) analysis, such as 50 to 250 m2 / g, such as 50 to 100 m2 / g, such as 100 to 150 m2 / g, such as 150 to 200 m2 / g, such as 200 to 250 m2 / g.

[0122] In one embodiment of the present disclosure, the catalyst support has a surface area of 100-150 m2 / g as determined by Brunauer-Emmett-Teller (BET) analysis.

[0123] In one embodiment of the present disclosure, the catalyst support has a surface area of 50-100 m2 / g as determined by Brunauer-Emmett-Teller (BET) analysis.

[0124] In one embodiment of the present disclosure, the catalyst support has a surface area of 200-250 m2 / g as determined by Brunauer-Emmett-Teller (BET) analysis.

[0125] BET analysis may be performed by following the methods known and appreciated within the field, such as N2 physical adsorption or physisorption. One such example of BET analysis methodology may be performed according to ISO 9277:2022. From BET analysis, further parameters such as total pore volume (Vtot) may be derived by the person skilled in the art without undue burden. Total pore volume (Vtot) may also be determined by gas physisorption (exemplary N2-physisorption) according to ISO 15901- 2:2022 by single point read of the absorption branch.

[0126] In one embodiment of the present disclosure, the catalyst support (porous solid support) has a total pore volume (Vtot) of 0.1 to 0.8 cm3 / g. In one embodiment of the present disclosure, the catalyst support has a total pore volume (Vtot) of 0.15 to 0.25 cm3 / g, or 0.30 to 0.45 cm3 / g, or 0.45 to 0.65 cm3 / g, or 0.65 to 0.80 cm3 / g determined by N2-physisorption, optionally according to ISO 15901-2:2022.

[0127] In one embodiment of the present disclosure, the catalyst support (porous solid support) has an average pore diameter (davg) of 3 to 30 nm determined by Barret- Joyner-Halenda (BJH) analysis. BJH analysis may be performed by evaluating N2 desorption processes following the DIN 66134:1998-02 protocol. In one or more embodiments of the present disclosure, the catalyst support has an average pore diameter (davg) of 3 to 5 nm, 5 to 7 nm, 7 to 10 nm, 10 to 13 nm, 13 to 17 nm, 17 to 20 nm, 20 to 25 nm, or 25 to 30 nm, as determined by Barret-Joyner-Halenda (BJH) analysis

[0128] Active metal loading

[0129] In one embodiment of the present disclosure wherein said catalyst composition is defined as comprising: a. a porous solid support, b. at least one catalytically active metal, and c. a eutectic metal salt composition or a precursor thereof, said eutectic metal salt composition comprising at least three different metal salt constituents, such as in a ternary eutectic salt, optionally wherein said eutectic composition is selected from ternary eutectic carbonate, ternary eutectic hydroxide, ternary eutectic nitrate and ternary eutectic chloride, or a mixture thereof, further wherein said eutectic metal salt composition is present in an amount corresponding to from 0.1 to 20 % of the total available porous support pore volume and / or wherein said eutectic metal salt composition makes up 0.1 to 20 % by weight of the catalyst composition, said at least one catalytically active metal (b) is comprised and / or present in the catalyst composition in an amount corresponding to from 1 to 20 % by weight of the total weight of the porous support (a) and the eutectic metal salt composition (c).

[0130] In one embodiment of the present disclosure wherein said catalyst composition is defined as comprising: a. a porous solid support, b. at least one catalytically active metal, and c. a eutectic metal salt composition or a precursor thereof, said eutectic metal salt composition comprising at least three different metal salt constituents, such as in a ternary eutectic salt, optionally wherein said eutectic composition is selected from ternary eutectic carbonate, ternary eutectic hydroxide, ternary eutectic nitrate and ternary eutectic chloride, or a mixture thereof, further wherein said eutectic metal salt composition makes up 0.1 to 20 % by weight of the catalyst composition, said at least one catalytically active metal (b) is comprised and / or present in the catalyst composition in an amount corresponding to from 1 to 20 % by weight of the total weight of the porous support (a) and the eutectic metal salt composition (c).

[0131] That is to say, in one embodiment of the present disclosure, the at least one catalytically active metal is present in the catalyst composition in an amount corresponding to from 1 to 20 % by weight of the total weight of porous solid support and eutectic metal salt composition.

[0132] In one embodiment of the present disclosure, the at least one catalytically active metal is present in the catalyst composition in an amount corresponding to from 2 to 6 % by weight of the total weight of porous solid support and eutectic metal salt composition.

[0133] In one embodiment of the present disclosure, the at least one catalytically active metal is present in the catalyst composition in an amount corresponding to 4 to 5 % by weight of the total weight of porous solid support and eutectic metal salt composition.

[0134] In one embodiment of the present disclosure, the at least one catalytically active metal is present in the catalyst composition in an amount corresponding to at least 0.5 % by weight of the total weight of porous solid support and eutectic metal salt composition.

[0135] In one embodiment of the present disclosure, the at least one catalytically active metal is present in the catalyst composition in an amount corresponding to at least 1.0 % by weight of the total weight of porous solid support and eutectic metal salt composition. In one embodiment of the present disclosure, the at least one catalytically active metal is present in the catalyst composition in an amount corresponding to at least 2.0 % by weight of the total weight of porous solid support and eutectic metal salt composition.

[0136] In one embodiment of the present disclosure, the at least one catalytically active metal is present in the catalyst composition in an amount corresponding to at least 4.0 % by weight of the total weight of porous solid support and eutectic metal salt composition.

[0137] Active metal element

[0138] In one embodiment of the present disclosure, the catalytically active metal is a transition metal or a d-block metal.

[0139] In one embodiment of the present disclosure, the catalytically active metal is a transition metal or a d-block metal selected from an element of groups 6 to 12 of the periodic table

[0140] In one embodiment of the present disclosure, the catalytically active metal is a transition metal selected from Ni, Cr, Mn, Fe, Co, Cu, Zn, Re, Mo, Rh, Ru, Ir, Pd, Pt, W, Cd, and Hg, or a binary or ternary mixture thereof.

[0141] In one embodiment of the present disclosure, the catalytically active metal is a transition metal selected from Ni, Co, Fe, Ru, Rh, Cu, Co, or a binary or ternary mixture thereof.

[0142] In one or more embodiments of the present disclosure, the catalytically active metal is a transition metal which is known to have a non-zero activity for the catalytic production of syngas, such as via the DRM reaction. Such metals include at least Ni, Co, Fe, Ru, Rh, Cu, Co, or a binary or ternary mixture thereof.

[0143] In one embodiment of the present disclosure, the catalytically active metal is Ni.

[0144] In one embodiment of the present disclosure, the catalytically active metal is a bimetallic alloy of Ni with one selected from Ru, Pd, Pt, Rh, Ir and Co. In one embodiment of the present disclosure, the catalytically active metal is a ternary alloy of Ni with two selected from Ru, Pd, Pt, Rh, Ir and Co.

[0145] In one embodiment of the present disclosure, the catalytically active metal is Ni and is present in an amount corresponding to 1-10 % by weight of the porous solid support.

[0146] In one embodiment of the present disclosure, the catalytically active metal is Ni and is present in an amount corresponding to 3-7 % by weight of the porous solid support.

[0147] In one embodiment of the present disclosure, the catalytically active metal is Ni and is present in an amount corresponding to 4-6 % by weight of the porous solid support.

[0148] In one embodiment of the present disclosure, the catalytically active metal is Ni and is present in an amount corresponding to 5 % by weight of the porous solid support.

[0149] Catalyst nanoparticle size

[0150] In one embodiment of the present disclosure, the catalytically active metal is present in the catalyst composition in the form of nanoparticles, such as discrete nanoparticles, having a diameter and / or size between 1-10 nm, such as 2-9 nm, such as 3-8 nm, such as 4-7 nm, such as 5-6 nm.

[0151] In one embodiment of the present disclosure, the catalytically active metal is present in the catalyst composition in the form of nanoparticles, such as discrete nanoparticles, having an average diameter and / or size between 1-10 nm, such as 2-9 nm, such as 3- 8 nm, such as 4-7 nm, such as 5-6 nm.

[0152] In one embodiment of the present disclosure, the catalytically active metal size distribution is characterized by a Dso between 1 nm to 10 nm, such as an integer between 2 nm to 9 nm, such as an integer between 3 nm to 8 nm, such as an integer between 4 nm to 7 nm, such as an integer between 5 nm to 6 nm.

[0153] In one embodiment of the present disclosure, the catalytically active metal size distribution is characterized by a Dso of less than 20 nm, such as 17 nm or less, such as 15 nm or less, such as 12 nm or less, such as 10 nm or less. In one embodiment of the present disclosure, the catalytically active metal size distribution is characterized by a D90 between 10 nm to 40 nm, such as an integer between 10 nm and 12 nm, such as an integer between 12 nm and 14 nm, such as an integer between 14 nm and 16 nm, such as an integer between 16 nm and 18 nm, such as an integer between 18 nm and 20 nm, such as an integer between 20 nm and 25 nm, such as an integer between 25 nm and 30 nm, such as an integer between 30 nm and 35 nm, such as an integer between 35 nm and 40 nm.

[0154] In one embodiment of the present disclosure, the catalytically active metal size distribution is characterized by a D90 of less than 20 nm, such as 17 nm or less, such as 15 nm or less, such as 12 nm or less, such as 10 nm or less.

[0155] In one embodiment of the present disclosure, the catalyst composition as described herein is catalyzing and / or is suitable for catalyzing the production of syngas from a feed mixture comprising at least methane and carbon dioxide, such as in dry reforming of methane (DRM). In particular, the catalyst composition as described herein is in the form of a solid composition comprising a coated and / or impregnated TEC part in relation to the porous support. As such, the composition does not comprise a catalyst submerged into a liquid eutectic melt. The catalyst composition described herein should thus be suitable for catalyzing the production of syngas in a reaction chamber commonly implemented in heterogenous catalysis, such as a plug-flow reactor, tubular reactor, multi-tubular reactor, fluidized bed reactor and fixed-bed reactor.

[0156] In one embodiment of the present disclosure, the catalyst composition as described herein is catalyzing and / or is suitable for catalyzing the production of carbon monoxide from a mixture of solid carbon and carbon dioxide, such as in the reverse Bouduard reaction.

[0157] Heterogenous catalysis

[0158] An embodiment of the present disclosure is also use of the catalyst as herein described in heterogenous catalysis, preferably in dry reforming of methane. In another embodiment, the heterogenous catalysis may be in reverse water-gas shift (RWGS)

[0159] RWGS is known to those in the art, and entails conversion of hydrogen and carbon dioxide into carbon monoxide and water. Within the scope of the present disclosure is also provided a method of catalytically producing syngas from a feed mixture comprising at least methane and carbon dioxide, said method making use of the catalyst composition of the present disclosure.

[0160] In one embodiment of the present disclosure for catalytically producing syngas, the method comprises a step of contacting the feed mixture comprising at least methane and carbon dioxide with the catalyst composition of the present disclosure.

[0161] In one embodiment of the present disclosure for catalytically producing syngas, the method is performed at a temperature of 400 to 800 °C.

[0162] In one embodiment of the present disclosure for catalytically producing syngas, the method is performed at a temperature of 600 °C to 800 °C, such as 700 °C.

[0163] In one embodiment of the present disclosure for catalytically producing syngas, the method is performed at ambient pressure.

[0164] In one embodiment of the present disclosure for catalytically producing syngas, the method is performed at pressure above 1 bar, such as above 3 bar, such as above 5 bar, such as above 7 bar, such as above 10 bar, such as above 15 bar, such as above 20 bar, such as above 25 bar.

[0165] In one embodiment of the present disclosure for catalytically producing syngas, the feed stream comprises a gas composition comprising at least methane and carbon dioxide having a flow rate of 45 mL / min, optionally further comprising a gas composition comprising nitrogen having a flow rate of 90 mL / min.

[0166] In one embodiment of the present disclosure for catalytically producing syngas, the CH4 / CO2 volumetric ratio is 1 :1 in the feed mixture.

[0167] In one embodiment of the present disclosure for catalytically producing syngas, the method is performed at a GSHV value is between 10-160.000 mL gcat'1h'1, preferably wherein the GSHV value is between 40.000 and 60.000 mL gcat'1h'1. As used herein, the term “GSHV” refers to gas hourly space velocity. In one embodiment of the present disclosure for catalytically producing syngas, the method is performed wherein the catalyst is provided as a particle fraction having a particle size between 180 pm and 355 pm.

[0168] In one embodiment of the present disclosure for catalytically producing syngas, the method further comprises a treatment step of reducing the catalyst composition of the present disclosure at a temperature higher than room temperature prior to the step of contacting the feed mixture comprising at least methane and carbon dioxide with the catalyst composition. This may also be referred to herein as a “pre-treatment” step.

[0169] In one embodiment of the present disclosure for catalytically producing syngas, the pre-treatment step comprise heating the catalyst to a temperature above room temperature in the presence of hydrogen gas, for a time sufficient to achieve reduction of the catalyst composition.

[0170] In one embodiment of the present disclosure for catalytically producing syngas, the pre-treatment step comprise heating the catalyst to a temperature of 800 °C at a heating ramp of 0.5-20 °C / min in a gas composition of 1-20 ml / min H2 and 20-100 ml / min N2, thereby reducing any metal oxides to catalytically active metal nanoparticles.

[0171] In one embodiment of the present disclosure for catalytically producing syngas, the pre-treatment step comprise heating the catalyst to a temperature of 800 °C at a heating ramp of 5 °C / min in a gas composition of 5 ml / min H2 and 45 ml / min N2, thereby reducing any metal oxides to catalytically active metal nanoparticles.

[0172] In one embodiment of the present disclosure for catalytically producing syngas, said syngas is catalytically produced via dry reforming of methane (DRM).

[0173] In one embodiment of the present disclosure for catalytically producing syngas, said produced syngas comprise a mixture of CO and hydrogen. In one embodiment of the present disclosure for catalytically producing syngas, said produced syngas comprise a CO and hydrogen (H2) in a ratio from 1 :2 at a temperature of 650 °C to 1 :1 at a temperature of 750 °C.

[0174] Coke mitigation

[0175] In one embodiment of the present disclosure for catalytically producing syngas, said catalyst composition inhibits formation of coke deposits during operation wherein the inhibition of coke deposits refers to the ability of the eutectic metal salt composition to reduce or prevent the accumulation of carbonaceous material on the catalytically active metal over time. This, in turn, slows the rate of catalyst deactivation, thereby maintaining higher catalytic activity over an extended period of operation.

[0176] In one embodiment of the present disclosure for catalytically producing syngas, said catalyst composition reduces coke deposits during operation, such as by oxidation and / or gasification.

[0177] In one embodiment of the present disclosure for catalytically producing syngas, said ternary eutectic salt is liquid and / or molten during operation.

[0178] In one embodiment of the present disclosure for catalytically producing syngas, said method comprise gasification of coke depositions.

[0179] In one embodiment of the present disclosure for catalytically producing syngas, said catalyst catalyzes or is capable of catalyzing the reverse Bouduard reaction.

[0180] In one embodiment of the present disclosure for catalytically producing syngas, said method is characterized by no formation of coke and / or carbonaceous deposits above 550 °C , such as above 600 °C.

[0181] Improvement of in opera ndo life-time

[0182] Within the scope of the present disclosure is also provided a method of improving in situ operation life-time of a heterogenous catalyst, such as especially relevant for heterogenous catalysts comprising exposed metal / catalyst surfaces prone to deactivation by carbon and / or coke depositions. An embodiment of the present disclosure therefore provides a method of improving in situ operation and / or in operando life-time of a heterogenous catalyst, said catalyst comprising a catalytically active metal having at least one catalytically active metal surface, wherein said metal surface is prone to deactivation (i.e. loss of catalytic activity) by coke formation and / or coke deposition on said metal surface, the method comprising at least partially coating said catalytically active metal surface with a eutectic metal salt composition or a precursor thereof, said eutectic metal salt composition comprising at least a ternary eutectic salt, optionally wherein said ternary eutectic salt is selected from alkali metal ternary eutectic carbonate, alkali metal ternary eutectic formate, alkali metal ternary eutectic hydroxide, alkali metal ternary eutectic nitrate and alkali metal ternary eutectic chloride, or a mixture thereof.

[0183] The term “operando" as used herein in relation to in operando life-time is to be construed as referring to “under reaction conditions”, specifically for in operando lifetime, to the effective functional duration of a catalyst under reaction conditions. The term is known in the field, and similar terms exist such as operando studies referring to analytical investigation of working catalysts under actual conditions allowing for coupled evaluation of e.g., structure and activity. It is important to highlight within the meaning of the present disclosure, that the life-time of a heterogenous catalyst is usually only discussed under operation conditions, because the (at times) harsh conditions of heterogenous catalysis has the risk of greatly impacting catalyst properties. At least partially coating a metal surface of a heterogenous catalyst with a ternary eutectic salt as described herein will not have an impact on the life-time of a catalyst, figuratively speaking, placed on a shelve (i.e. not taking part in a catalytic reaction). It will however be immediately evident that under operation conditions, i.e. in operando, the life-time is greatly improved, in particular by the prevention of coke formations on the catalyst metal surface in those situations where the metal surface is susceptible to carbon deactivation and / or depositions, in particular relevant for coinage metals such as Ni.

[0184] An improvement within the context of the present disclosure, such as when referring to improving the in operando life time of the catalyst, should be seen as providing at least 5% or more, such as 10% or more, such as 20% or more of at least one beneficial property related to catalytic production of syngas. Such improvement may be compared to a standard baseline catalyst, such as a catalyst which has not been subjected to a TEC coating of the present invention, and may be evaluated after a predetermined time of operation under catalytic conditions, such as 5 hours or more, 10 hours or more, 20 hours or more, 50 hours or more, 100 hours or more, 120 hours or more, 150 hours or more, 200 hours or more.

[0185] Exemplary, a non-TEC coated 5wt%Ni / YSZ catalyst as presented in Example 1 may after 50 hours of operation under DRM conditions (described in Example 1) only retain 81% of its original CO2 reforming activity which represents a 19% loss of activity. Opposed to this, the TEC-coated equivalent (also presented in Example 1) retains 91% of its original CO2 reforming activity after the same period of operation, corresponding only to a 9% loss of activity (see e.g., Fig. 4B). As such, the activity of the TEC-coated catalyst provided an improvement in the form of a decreased rate of deactivation, the rate of deactivation being improved / lowered by more than 10% as determined after 50 hours of operation.

[0186] Moreover, the improvement will be readily discernible from the data-readout during catalyst operation, such as substrate / feed conversions and product yields which will decrease gradually over time as the support pores and / or active catalyst sites are blocked by coke, which predominantly takes effect in the catalyst not having a TEC coating. Furthermore, post-operation analysis such as temperature-programmed oxidation (TPO) may be used to determine the total amount of coke-deposits on the catalyst by oxidation to carbon dioxide and measuring the liberated CO2 amounts by gas-phase chromatography (GC-MS).

[0187] In one embodiment of the present disclosure for improving catalyst life-time, said step of partially coating said catalytically active metal surface with a eutectic metal salt composition or a precursor thereof, provides an improved in situ operation and / or in operando life-time by providing at least one or more of the following beneficial properties: a. decreased rate of deactivation, such as decreased rate of deactivation for the first 20 hours of operation, such as for the first 50 hours of operation; b. decreased rate of coke and / or carbon deposition, such as decreased rate of coke and / or carbon deposition for the first 20 hours or more of operation, such as after 50 hours or more of operation; c. decreased amount of coke and / or carbon deposition, such as decreased amount of coke and / or carbon deposition at 20 hours or more of operation, such as after 50 hours or more of operation; d. increased catalytic activity for DRM after 16 hours of operation, such as after 20 hours of operation, such as after 50 hours of operation; and e. formation of only one distinct type of coke deposits on said metal surface, such as formation of only one distinct type of coke deposits on said metal surface after 20 or more hours of operation, such as after 50 hours or more of operation, such as after 100 hours or more of operation; each of the above being evaluated as when compared against a similar heterogenous catalyst not having been subjected to the same step of partially coating said catalytically active metal surface with a ternary eutectic metal salt composition or a precursor thereof (TEC coating).

[0188] In one embodiment of the present disclosure for improving catalyst life-time, said in operando is heterogenous catalysis of a reaction involving carbon dioxide and / or carbon monoxide, preferably carbon dioxide.

[0189] In one embodiment of the present disclosure for improving catalyst life-time, said in operando is heterogenous catalysis, specifically dry reforming of methane.

[0190] In one embodiment of the present disclosure for improving catalyst life-time, said ternary eutectic salt is liquid and / or molten during operation.

[0191] In one embodiment of the present disclosure for improving catalyst life-time, said ternary eutectic carbonate is liquid and / or molten during operation.

[0192] In one embodiment of the present disclosure for improving catalyst life-time, said ternary eutectic salt reduces and / or inhibits formation of coke deposits during operation, such as by gasification.

[0193] In one embodiment of the present disclosure for improving catalyst life-time, said ternary eutectic salt is a catalyst of and / or catalyzes the reverse Bouduard reaction. In one embodiment of the present disclosure for improving catalyst life-time, said ternary eutectic carbonate reduces and / or inhibits formation of coke deposits during operation, such as by gasification.

[0194] In one embodiment of the present disclosure for improving catalyst life-time, said ternary eutectic carbonate is a catalyst of and / or catalyzes the reverse Bouduard reaction.

[0195] In one embodiment of the present disclosure for improving catalyst life-time, formation of coke deposits during operation is reduced and / or inhibited for at least 20 hours of operation, such as at least 100 hours of operation.

[0196] In one embodiment of the present disclosure for improving catalyst life-time, said partially coated heterogenous catalyst is characterized by no formation of coke and / or carbonaceous deposits above 600 °C.

[0197] In one embodiment of the present disclosure is also provided a method for reducing coke formations and / or coke depositions on a catalyst taking part in, such as during, a carbon gaseous reforming reaction such as dry reforming of methane (DRM). In one embodiment of the present disclosure the method comprises at least partially coating the catalyst with a ternary eutectic salt as described herein in an amount corresponding to from 0.1 to 20 % by weight of the catalyst. The coke formations or coke depositions may be in the form of carbon whiskers known in the art.

[0198] Method of manufacture

[0199] Within the scope of the present disclosure is also provided a method of producing the catalyst composition disclosed herein, i.e. a catalyst composition comprising: a. a porous solid support, b. at least one catalytically active metal, and c. a eutectic metal salt composition or a precursor thereof, said eutectic metal salt composition comprising at least three different metal salt constituents, such as in a ternary eutectic salt, further wherein said eutectic metal salt composition is present in an amount corresponding to from 0.1 to 20 % of the total available porous support pore volume and / or wherein said eutectic metal salt composition makes up 0.1 to 20 % by weight of the catalyst composition.

[0200] In one embodiment of the present disclosure is provided a method for producing the catalyst as described herein, the method comprising the steps: a. providing a porous oxide support; b. impregnating a solution comprising at least one transition metal into said oxide support to prepare a transition metal impregnated support; c. drying and calcining said transition metal impregnated support to provide a calcined transition metal impregnated support; d. impregnating a solution comprising at least three distinct alkali metals into said calcined transition metal impregnated support to provide an alkali impregnated support; and e. drying and calcining said alkali impregnated support to obtain a catalyst, optionally wherein said calcination is performed under a gaseous flow comprising ambient air or air comprising at least an amount of carbon dioxide;

[0201] In one embodiment of the present disclosure for catalyst manufacture, said steps c and e may comprise drying at 80 °C for at least 4 hours, and subsequently calcining at a temperature of at least 425 °C, such as at 500 °C for at least 2 hours, preferably with a temperature ramp of 5 °C / min.

[0202] In one embodiment, steps c and / or d may individually be performed in atmospheric air or in a gas mixture comprising a source of carbon dioxide.

[0203] In one embodiment of the present disclosure for catalyst manufacture, said method may further optionally comprise a step of reducing said transition metal impregnated support prior to step d (impregnation with at least three distinct alkali metals). Said reduction may in one embodiment be performed in the presence of gaseous hydrogen and is preferably conducted above room temperature, such as exemplary above 400 °C. The reduction process may be evaluated for completion using e.g. temperature programmed reduction (TPR) analysis known to those skilled in the art. In one embodiment of the present disclosure for catalyst manufacture, said method may optionally comprise a step of reducing said catalyst subsequent to step e (drying and calcining said alkali impregnated support). Said reduction (step f) may in one embodiment be performed in the presence of gaseous hydrogen and is preferably conducted above room temperature, such as exemplary above 400 °C. The reduction process may be evaluated for completion using e.g. temperature programmed reduction (TPR) analysis known to those skilled in the art.

[0204] In one embodiment of the present disclosure for catalyst manufacture, said solution comprising at least one transition metal of step b is provided as the nitrate, acetate, carbonate or halide salt of said transition metal. In one embodiment, the transition metal of step b is selected as one or more from the group consisting of Ni, Co, Fe, Ru, Rh, Cu and Co. In one embodiment the transition metal is Ni.

[0205] In one embodiment of the present disclosure for catalyst manufacture, said solution comprising at least three distinct alkali metals of step d is provided as the formate, nitrate, carbonate, hydroxide or halide salt of alkali metals. In one embodiment, the three distinct alkali metals of step d are individually selected from the group consisting of Li, Na, K, Rb and Cs. In one embodiment the three distinct alkali metals are Li, Na and K and are preferably provided as their salts in a weight ratio of 1 :1 :1 in the solution of step d.

[0206] In one embodiment of the present disclosure for catalyst manufacture, said solution comprising at least three distinct alkali metals of step d is provided in an amount corresponding to a final TEC loading of from 0.1 to 20 % of the total available porous support pore volume, and / or from 0.1 to 20 wt% of the total catalyst weight.

[0207] Within the scope of the present disclosure is also use of a catalyst obtained by the method of manufacture described herein above, for use in heterogenous catalysis, preferably in dry reforming of methane, or in reverse water-gas shift (RWGS) reaction, or for producing syngas from a feed mixture comprising at least methane and carbon dioxide.

[0208] Examples Example 1 preparation of 1 g of 1% TEC / 5 wt% Ni / ZrO2 using alkali formates and Ni nitrate as precursors.

[0209] Materials:

[0210] Nickel nitrate (Ni(NO3)2'6H2O, Sigma-Aldrich), lithium formate monohydrate (HCChLi ■ H2O, Sigma-Aldrich), sodium formate (HCOONa, Sigma-Aldrich) and potassium formate (HCOOK, Sigma-Aldrich), 3 mol% Y-stabilized zirconium oxide (YSZ, Saint-Gobain)

[0211] Table 1. Results from I\l2-physisorption analysis performed at 77 K,aSpecific surface area, SBET, calculated by the BET method.bTotal pore volume, Vtot, determined from a single point read of the adsorption branch at p / po=O.95.cAverage pore diameter, davg, calculated by the BJH method.

[0212] 994 mg of 3 mol% YSZ was measured and put in a small cylindrical container. Hereafter, 250 mg of Ni(NO3)2'6H2O was put in another container and dissolved in 90% of the total pore volume of the YSZ, corresponding to 188 pL while gently heating.

[0213] The dissolved Ni(NOs)2 mixture is then added slowly dropwise to the small cylindrical container with YSZ while rigorously stirring to ensure even distribution of the Ni- precursor.

[0214] The resulting impregnated YSZ is dried overnight at 80 °C, then put into an oven and calcined at 500 °C in atmospheric air for 2 hours with a ramp of 5 °C / min. The resulting material consists essentially of NiO on YSZ.

[0215] To further reduce the NiO, the material is put into a tubular oven, and under a constant flow of 10 vol% H2 in N2, the material is heated to 800 °C with a ramp of 5 °C / min and held for 4 hours. The resulting catalysts now consist of Ni° / YSZ and are ready to be impregnated with the TEC promoter.

[0216] The mass ratio of the TEC mixture is calculated to consist of 31.6%, 33.6%, and 34.8% of U2CO3, Na2COs, and K2CO3, respectively. The starting precursor is the formate salts of each alkali metal, HCO2I H2O, HCChNa, and HCO2K.

[0217] The resulting reduced catalyst is now put into a small cylindrical container. In another container is placed, 6.1 mg, 4.3 mg, and 4.2 mg of HCO2I H2O, HCChNa, and HCO2K, respectively. The formate precursor mixture was put into an aqueous solution of demineralized water corresponding to 80% of the pore volume of the implemented YSZ, equal to 168 pL. (Only 80% of pore volume due to the reduction of pore volume due to the impregnation with Ni.) The dissolved alkali precursor mixture is added dropwise to the container with Ni° / YSZ while stirred rigorously.

[0218] The TEC precursor-impregnated Ni° / YSZ catalyst is dried overnight at 80 °C and hereafter calcined at 500 °C for 4 hours with a ramp of 5 °C / min under a stable flow of CO2 (30 ml / min, 1 bar, 23 °C). The formate precursors readily decompose and form their resulting alkali carbonate salts.

[0219] After the last CO2 calcination, the catalyst is fractionated to 180-355 pm and ready to be tested.

[0220] Catalytic tests:

[0221] All activity tests were conducted at atmospheric pressure in a plug flow Microactivity- Effi reactor (PID Eng&Tech) equipped with an automatic liquid-gas separator and mass flow controllers for CO2, H2 and N2. The reaction products were periodically analyzed using a 7820A GC from Agilent Technologies equipped with 3 columns of 3.2 mm outer diameter (OD) and 2 mm inner diameter (ID). Column materials of the 3 columns was (individually) Porapak Q (1.83 m), Porapak Q (0.91 m), and MolSieve 5A (1.83 m), all provided by Agilent Technologies. The catalyst bed consisted of fractionated catalysts (150 mg, 180-355 pm) diluted in fractionated inactive quartz sand (1 g, 180-355 pm) fixed by two pieces of quartz wool in a quartz reactor. Before catalytic testing, the catalyst was reduced which was typically performed at 800 °C with a heating ramp of 5 °C / min in a gas composition of 5 mL / min H2 and 45 mL / min N2.

[0222] For the temperature profiles, catalysts were cooled to 300 °C before heating with a ramp of 5 °C / min, and the reaction products were analyzed every 30 minutes. For the stability tests, we typically test the catalyst up to 700 °C with a heating ramp of 5 °C / min in a gas composition of 45 mL / min CFkCCh (1 :1) and 90 mL / min N2 with the reaction product analyzed every hour.

[0223] SEM analysis:

[0224] Samples were prepared by dispersion onto carbon adhesive tabs mounted on a stub and analysed using a FEI Helios Nanolab 660 FIB-SEM (focused ion beam scanning electron microscope). Imaging was conducted in immersion mode measuring secondary electrons with an Everhart-Thornley detector. The instrument was operated at an accelerating voltage of 10 kV, a beam current of 86 pA, and magnifications ranging from 5,000 to 35,000 under ultra-high vacuum conditions.

[0225] Example 2 preparation of 1 g of 1wt% TEC / 5 wt% Ni / AI2O3 and 1 g of 1 wt% TEC / 5 wt% Ni / MgAhC using alkali formates and Ni nitrate as precursors.

[0226] Materials:

[0227] Nickel nitrate (Ni(NO3)2'6H2O, Sigma-Aldrich), lithium formate monohydrate (HCO2U ■ H2O, Sigma-Aldrich), sodium formate (HCOONa, Sigma-Aldrich) and potassium formate (HCOOK, Sigma-Aldrich), aluminum oxide (AI2O3, Saint-Gobain), magnesium aluminum oxide (spinel, MgAhOt, Saint-Gobain)

[0228] Table 2. Results from I\l2-physisorption analysis performed at 77 K, a Specific surface area, SBET, calculated by the BET method.bTotal pore volume, Vtot, determined from a single point read of the adsorption branch at p / po=O.95.cAverage pore diameter, davg, calculated by the BJH method.

[0229] 940 mg of AI2O3 or MgAhO4 was measured and put in a small cylindrical container. Hereafter, 248 mg of Ni(NO3)2'6H2O was put in another container and dissolved in 90% of the total pore volume of the AI2O3 or MgAhO4, corresponding to 525 or 280 pL, respectively.

[0230] The Ni(NOs)2 aqueous solution is then added slowly dropwise to the small cylindrical container with AI2O3 or MgAhO4 while rigorously stirring to ensure even distribution of the Ni-precursor.

[0231] The resulting metal catalyst-impregnated AI2O3 or MgAhO4 is dried overnight at 80 °C, then put into an oven and calcined at 500 °C in atmospheric air for 2 hours with a ramp of 3 °C / min. The resulting material consists of NiO on AI2O3 or NiO on MgAhO4, respectively.

[0232] The mass ratio of the TEC mixture is calculated to consist of 31.6%, 33.6%, and 34.8% of U2CO3, Na2CO3, and K2CO3, respectively. The starting precursor is the formate salts of each alkali metal, HCO2Li H2O, HCO2Na, and HCO2K. The resulting calcined catalyst is now put into a small cylindrical container. In another container, 6.1 mg, 4.3 mg, and 4.2 mg of HCO2I H2O, HCChNa, and HCO2K, respectively. The formate precursor mixture was put into a solution with 90 % of the pore volume of impregnated with Ni and calcined AI2O3 and MgAhOt, equal to 465 and 254 pL. (Observed lower pore volume due to the impregnation of Ni(NOa)2 followed by calcination at 500 °C). The dissolved alkali precursor mixture is added dropwise to the container consisting of NiO / AhOa and NiO / MgAhO4 while stirred rigorously.

[0233] The TEC precursor-impregnated Ni / AhOa / MgAhO^s dried overnight at 80 °C and hereafter calcined at 500 °C for 3 hours with a ramp of 3 °C / min and a stable flow of CO2. The formate precursors readily decompose and form their resulting alkali carbonate salts.

[0234] After the last CO2 calcination, the catalyst is fractionated to 180-355 pm and are loaded to the plug-flow reactor, where it is calcined in reducing atmosphere (10% H2 / N2) at 700 °C and held for 2 hours with a ramp of 10 °C / min. The catalyst is then flushed with N2 flow (50 ml / min) and then cooled in In flow to 300 °C, and the gas stream are changed to reaction mixture and the catalytic testing is started. Catalytic tests for these systems were done according to the procedure outlined in Example 1. Stability tests were done at 650 °C with a heating ramp of 5 °C / min in a gas composition of 35 mL / min CH^CCh (1 :1) and 140 mL / min N2 with the reaction product analyzed every hour.

[0235] Items 1

[0236] 1 . A catalyst composition comprising: a. a porous solid support, b. at least one catalytically active metal, and c. a eutectic metal salt composition or a precursor thereof, said eutectic metal salt composition comprising at least a ternary eutectic salt, optionally wherein said ternary eutectic salt is selected from ternary eutectic carbonate, ternary eutectic formate, ternary eutectic hydroxide, ternary eutectic nitrate and ternary eutectic chloride, or a mixture thereof, further wherein the eutectic metal salt composition is present in an amount corresponding to from 0.1 to 20 % of the total available porous support pore volume. 2. The catalyst according to any one of the preceding items, wherein the catalyst is a catalyst composite.

[0237] 3. The catalyst according to any one of the preceding items, wherein the eutectic metal salt composition optionally further comprises one or more of a second salt.

[0238] 4. The catalyst according to any one of the preceding items, wherein the one or more second salt is selected from the group consisting of alkali metal salt, earth-alkali metal salt, p-block metal salt, d-block metal salt and f-block metal salt.

[0239] 5. The catalyst according to any one of the preceding items, wherein the ternary eutectic salt is ternary eutectic carbonate or a ternary eutectic salt composition suitable for being transformed into the corresponding carbonate upon exposure to gaseous carbon dioxide, such as ternary eutectic formate, ternary eutectic hydroxide, ternary eutectic nitrate and ternary eutectic chloride, or a mixture thereof.

[0240] 6. The catalyst according to any one of the preceding items, wherein the ternary eutectic salt, such as ternary eutectic carbonate, ternary eutectic formate, ternary eutectic hydroxide, ternary eutectic nitrate and ternary eutectic chloride, or a mixture thereof is an alkali metal or alkaline earth metal ternary eutectic salt.

[0241] 7. The catalyst according to any one of the preceding items, wherein the ternary eutectic salt is ternary eutectic carbonate.

[0242] 8. The catalyst according to any one of the preceding items, wherein the ternary eutectic carbonate is an alkali metal or alkaline earth metal ternary eutectic carbonate.

[0243] 9. The catalyst according to any one of the preceding items, wherein the ternary eutectic carbonate is comprised of three distinct carbonate salts individually selected from U2CO3, Na2CO3, K2CO3, Rb2CO3, CS2CO3, MgCCh, CaCCh, SrCCh, and BaCCh, or a hydrate thereof.

[0244] 10. The catalyst according to any one of the preceding items, wherein the alkali metal ternary eutectic is comprised of three distinct alkali metal salts individually selected from U2CO3, Na2CO3, K2CO3, Rb2CO3, and CS2CO3, or a hydrate thereof.

[0245] 11 . The catalyst according to any one of the preceding items, wherein the ternary eutectic salt is ternary eutectic formate.

[0246] 12. The catalyst according to any one of the preceding items, wherein the ternary eutectic formate comprises at least three formate salts individually selected from Li(O2CH), Na(O2CH), K(O2CH), Rb(O2CH), Cs(O2CH), Mg(O2CH)2, Ca(C>2CH)2, Sr(C>2CH)2, and Ba(C>2CH)2, or a hydrate thereof.

[0247] 13. The catalyst according to any one of the preceding items, wherein the ternary eutectic salt is ternary eutectic hydroxide.

[0248] 14. The catalyst according to any one of the preceding items, wherein the ternary eutectic hydroxide comprises at least three hydroxide salts individually selected from LiOH, NaOH, KOH, RbOH. CsOH, Mg(OH)2, Ca(OH)2, Sr(OH)2, and Ba(OH)2, or a hydrate thereof.

[0249] 15. The catalyst according to any one of the preceding items, wherein the ternary eutectic salt is ternary eutectic nitrate.

[0250] 16. The catalyst according to any one of the preceding items, wherein the ternary eutectic nitrate comprises at least three nitrate salts individually selected from UNO3, NaNO3, KNO3, RbNO3, CsNO3, Mg(NO3)2, Ca(NO3)2, Sr(NO3)2, and Ba(NOs)2, or a hydrate thereof.

[0251] 17. The catalyst according to any one of the preceding items, wherein the ternary eutectic salt is ternary eutectic chloride. 18. The catalyst according to any one of the preceding items, wherein the ternary eutectic chloride comprises at least three chloride salts individually selected from LiCI, NaCI, KCI, RbCI, CsCI, MgCh, CaCh, SrCh, and BaCh, or a hydrate thereof.

[0252] 19. The catalyst according to any one of the preceding items, wherein ternary eutectic salt is an alkali metal ternary eutectic salt, such as alkali metal ternary carbonate, formate, nitrate, hydroxide, or chloride.

[0253] 20. The catalyst according to any one of the preceding items, wherein the ternary eutectic salt comprise U2CO3, Na2COs and K2CO3.

[0254] 21 . The catalyst according to any one of the preceding items, wherein the ternary eutectic salt comprise U2CO3, Na2COs and K2CO3 in an amount corresponding to 1 : 1 : 1 by weight of the eutectic composition.

[0255] 22. The catalyst according to any one of the preceding items, wherein the ternary eutectic salt comprise 33 (±2) wt% U2CO3; 33 (±2) wt% K2CO3; 33 (±2) wt% Na2CC>3 by weight of the eutectic composition.

[0256] 23. The catalyst according to any one of the preceding items, wherein the ternary eutectic salt comprise 32.1 (±1.0) wt% U2CO3; 34.5 (±1.0) wt% K2CO3; 33.4 (±1 .0) wt% Na2CC>3 by weight of the eutectic composition.

[0257] 24. The catalyst according to any one of the preceding items, wherein the ternary eutectic salt comprise U2CO3 : K2CO3 : Na2COs in a molar ratio of 43.5 : 25 : 31.5

[0258] 25. The catalyst according to any one of the preceding items, wherein the ternary eutectic salt has a melting point in the range of 390 °C to 600 °C, such as 390 °C to 400 °C, such as 400 °C to 450 °C, such as 450 °C to 500 °C, such as 500 °C to 550 °C, such as 550 °C to 600 °C.

[0259] 26. The catalyst according to any one of the preceding items, wherein the ternary eutectic salt has a melting point in the range of 397 °C to 410 °C. 27. The catalyst according to any one of the preceding items, wherein the ternary eutectic salt is present in an amount corresponding to from 0.1 to 20 wt% of the total catalyst weight, such as from 0.1 to 1.0 wt%, such as from 1.0 to 2.0 wt%, such as from 2.0 to 3.0 wt%, such as from 3.0 to 4.0 wt%, such as from 4.0 to 5.0 wt%, such as from 5.0 to 7.0 wt%, such as from 7.0 to 10 wt%, such as from 10 wt% to 20 wt%.

[0260] 28. The catalyst according to any one of the preceding items, wherein the ternary eutectic salt is present in an amount corresponding to from 0.5 to 5 wt% of the total catalyst weight, such as 0.5 wt%, 1 .0 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%, 3.0 wt%, 3.5 wt%, 4.0 wt%, 4.5 wt% or 5.0 wt%.

[0261] 29. The catalyst according to any one of the preceding items, wherein the ternary eutectic salt is present in an amount corresponding to from 0.1 to 20 % of the total available porous support pore volume, such as from 0.1 to 1.0 %, such as from 1 .0 to 2.0 %, such as from 2.0 to 3.0 %, such as from 3.0 to 4.0 %, such as from 4.0 to 5.0 %, such as from 5.0 to 7.0 %, such as from 7.0 to 10 %, such as from 10 % to 20 %.

[0262] 30. The catalyst according to any one of the preceding items, wherein the ternary eutectic salt is present in an amount corresponding to from 0.5 to 5 % of the total available porous support pore volume, such as 0.5 %, 1.0 %, 1.5 %, 2.0 %, 2.5 %, 3.0 %, 3.5 %, 4.0 %, 4.5 % or 5.0 %.

[0263] Support

[0264] 31. The catalyst according to any one of the preceding items, wherein said solid support is a ceramic support, such as a oxides and / or nitrides and / or carbonates and / or chlorides of one or more metals including mixtures thereof.

[0265] 32. The catalyst according to any one of the preceding items, wherein said ceramic support is selected from ZrC>2, CeC>2, AI2O3, TiC>2, SiC>2, CaO, K2O, MgCh, SiaN4, MgAhOt, BaO, SrTiCh, La2Os, MgO, CaTiCh, BaTiCh and zeolites such as GME, FAU, ANA, MOR, HEU, LTA, and MFI zeolite types, and mixtures thereof. 33. The catalyst according to any one of the preceding items, wherein said ceramic support is selected from ZrC>2, CeC>2, MgAhOt and mixtures thereof.

[0266] 34. The catalyst according to any one of the preceding items, further comprising at least one doping ion and / or metal which increases the thermal stability of the support.

[0267] 35. The catalyst according to any one of the preceding items, further comprising at least one doping ion and / or metal optionally, wherein said doping ion and / or metal increases the number of oxygen vacancies in the support.

[0268] 36. The catalyst according to any one of the preceding items, wherein the at least one doping ion and / or metal is yttrium, lanthanum, silicon, magnesium, calcium.

[0269] 37. The catalyst according to any one of the preceding items, wherein the at least one doping ion and / or metal is yttrium.

[0270] Surface area and pore volume

[0271] 38. The catalyst according to any one of the preceding items, wherein the catalyst support has a surface area of 50 to 250 m2 / g as determined by Brunauer- Emmett-Teller (BET) analysis, such as 50 to 250 m2 / g, such as 50 to 100 m2 / g, such as 100 to 150 m2 / g, such as 150 to 200 m2 / g, such as 200 to 250 m2 / g.

[0272] 39. The catalyst according to any one of the preceding items, wherein the catalyst support has a surface area of 100-150 m2 / g as determined by Brunauer- Emmett-Teller (BET) analysis.

[0273] 40. The catalyst according to any one of the preceding items, wherein the catalyst support has a total pore volume (Vtot) of 0.1 to 0.5 cm3 / g.

[0274] 41 . The catalyst according to any one of the preceding items, wherein the catalyst support has an average pore diameter (davg) of 3 to 10 nm determined by Barret-Joyner-Halenda (BJH) analysis. Active metal loading

[0275] 42. The catalyst according to any one of the preceding items, wherein the catalytically active metal is present in the catalyst composition in an amount corresponding to from 1 to 20 % by weight of the total weight of porous solid support and eutectic metal salt composition.

[0276] 43. The catalyst according to any one of the preceding items, wherein the catalytically active metal is present in the catalyst composition in an amount corresponding to from 2 to 6 % by weight of the total weight of porous solid support and eutectic metal salt composition.

[0277] 44. The catalyst according to any one of the preceding items, wherein the catalytically active metal is present in the catalyst composition in an amount corresponding to 4 to 5 % by weight of the total weight of porous solid support and eutectic metal salt composition.

[0278] Active metal element

[0279] 45. The catalyst according to any one of the preceding items, wherein the catalytically active metal is a transition metal.

[0280] 46. The catalyst according to any one of the preceding items, wherein, the catalytically active metal is a transition metal selected from an element of groups 6 to 12 of the periodic table.

[0281] 47. The catalyst according to any one of the preceding items, wherein the catalytically active metal is a transition metal selected from Ni, Cr, Mn, Fe, Co, Cu, Zn, Re, Mo, Rh, Ru, Ir, Pd, Pt, W, Cd, and Hg, or a binary or ternary mixture thereof.

[0282] 48. The catalyst according to any one of the preceding items, wherein the catalytically active metal is a transition metal selected from Ni, Co, Fe, Ru, Rh, Cu, Co, or a binary or ternary mixture thereof.

[0283] 49. The catalyst according to any one of the preceding items, wherein the catalytically active metal is Ni. 50. The catalyst according to any one of the preceding items, wherein the catalytically active metal is Ni and is present in an amount corresponding to 5 % by weight of the porous solid support.

[0284] Catalyst metal NP size

[0285] 51. The catalyst according to any one of the preceding items, wherein the catalytically active metal is present in the catalyst composition in the form of nanoparticles, such as discrete nanoparticles, having a diameter and / or size between 1-10 nm, such as 2-9 nm, such as 3-8 nm, such as 4-7 nm, such as 5- 6 nm.

[0286] 52. The catalyst according to any one of the preceding items, wherein the catalytically active metal is present in the catalyst composition in the form of nanoparticles, such as discrete nanoparticles, having an average diameter and / or size between 1-10 nm, such as 2-9 nm, such as 3-8 nm, such as 4-7 nm, such as 5-6 nm.

[0287] 53. The catalyst according to any one of the preceding items, wherein the catalytically active metal size distribution is characterized by a Dso between 1 nm to 10 nm, such as an integer between 2 nm to 9 nm, such as an integer between 3 nm to 8 nm, such as an integer between 4 nm to 7 nm, such as an integer between 5 nm to 6 nm.

[0288] 54. The catalyst according to any one of the preceding items, wherein the catalytically active metal size distribution is characterized by a Dso of less than 20 nm, such as 17 nm or less, such as 15 nm or less, such as 12 nm or less, such as 10 nm or less.

[0289] 55. The catalyst according to any one of the preceding items, wherein the catalytically active metal size distribution is characterized by a D90 between 10 nm to 40 nm, such as an integer between 10 nm and 12 nm, such as an integer between 12 nm and 14 nm, such as an integer between 14 nm and 16 nm, such as an integer between 16 nm and 18 nm, such as an integer between 18 nm and 20 nm, such as an integer between 20 nm and 25 nm, such as an integer between 25 nm and 30 nm, such as an integer between 30 nm and 35 nm, such as an integer between 35 nm and 40 nm.

[0290] 56. The catalyst according to any one of the preceding items, wherein the catalytically active metal size distribution is characterized by a D90 of less than 20 nm, such as 17 nm or less, such as 15 nm or less, such as 12 nm or less, such as 10 nm or less.

[0291] 57. The catalyst according to any one of the preceding items, wherein said catalyst composition is suitable for catalyzing the production of syngas from a feed mixture comprising at least methane and carbon dioxide, such as in dry reforming of methane (DRM).

[0292] Method for DRM

[0293] 58. A method for catalytically producing syngas from a feed mixture comprising at least methane and carbon dioxide, said method making use of the catalyst composition of any one of items 1 to 57.

[0294] 59. The method according to the previous item, comprising a step of contacting the feed mixture comprising at least methane and carbon dioxide with the catalyst composition of any one of items 1 to 57.

[0295] 60. The method according to any one of the preceding items, wherein the production of syngas is performed at a temperature of 400 to 800 °C.

[0296] 61. The method according to any one of the preceding items, wherein the production of syngas is performed at a temperature of 600 °C to 800 °C, such as 700 °C.

[0297] 62. The method according to any one of the preceding items wherein the feed stream comprises a gas composition comprising at least methane and carbon dioxide having a flow rate of 45 mL / min. 63. The method according to any one of the preceding items wherein the feed stream further comprises a gas composition comprising nitrogen having a flow rate of 90 mL / min.

[0298] 64. The method according to any one of the preceding items, wherein the CH4 / CO2 volumetric ratio is 1 :1 in the feed mixture.

[0299] 65. The method according to any one of the preceding items, wherein the GSHV value is between 10-160.000 mL gcat'1h'1, preferably wherein the GSHV value is between 40.000 and 60.000 mL gcat'1h'1.

[0300] 66. The method according to any one of the preceding items, wherein the catalyst is provided as a particle fraction having a particle size between 180 pm and 355 pm.

[0301] Pre-treatment reduction

[0302] Q7. The method according to any one of the preceding items, further comprising a pre-treatment step of reducing the catalyst composition of any one of items 1 to 57 at a temperature higher than room temperature prior to the step of contacting the feed mixture comprising at least methane and carbon dioxide with the catalyst composition.

[0303] 68. The method according to any one of the preceding items, wherein the pretreatment step comprise heating the catalyst to a temperature of 800 °C at a heating ramp of 0.5-20 °C / min in a gas composition of 1-20 ml / min H2 and 20- 100 ml / min N2, thereby reducing any metal oxides to catalytically active metal nanoparticles.

[0304] 69. The method according to any one of the preceding items, wherein the pretreatment step comprise heating the catalyst to a temperature of 800 °C at a heating ramp of 5 °C / min in a gas composition of 5 ml / min H2 and 45 ml / min N2, thereby reducing any metal oxides to catalytically active metal nanoparticles. 70. The method according to any one of the preceding items, wherein said syngas is catalytically produced via dry reforming of methane (DRM).

[0305] 71. The method according to any one of the preceding items, wherein said produced syngas comprise a mixture of CO and hydrogen.

[0306] 72. The method according to any one of the preceding items, wherein said produced syngas comprise a CO and H2 in a ratio from 1 :2 at a temperature of 650 °C to 1:1 at a temperature of 750 °C.

[0307] Coke mitigation

[0308] 73. The method according to any one of the preceding items, wherein said catalyst composition inhibits formation of coke deposits during operation.

[0309] 74. The method according to any one of the preceding items, wherein said catalyst composition reduces coke deposits during operation, such as by oxidation and / or gasification.

[0310] 75. The method according to any one of the preceding items, wherein said ternary eutectic salt is liquid and / or molten during operation.

[0311] 76. The method according to any one of the preceding items, wherein said method comprise gasification of coke depositions.

[0312] 77. The method according to any one of the preceding items, wherein said catalyst catalyzes or is capable of catalyzing the reverse Bouduard reaction.

[0313] Functionally described method

[0314] 78. A method of improving in situ operation and / or in operando life-time of a heterogenous catalyst comprising a catalytically active metal having at least one catalytically active metal surface, wherein said metal surface is prone to catalysis deactivation by coke formation and / or deposition on said metal surface, the method comprising at least partially coating said catalytically active metal surface with a eutectic metal salt composition or a precursor thereof, said eutectic metal salt composition comprising at least a ternary eutectic salt, optionally wherein said ternary eutectic salt is selected from alkali metal ternary eutectic carbonate, alkali metal ternary eutectic formate, alkali metal ternary eutectic hydroxide, alkali metal ternary eutectic nitrate and alkali metal ternary eutectic chloride, or a mixture thereof,

[0315] 79. The method according to any one of the preceding items, wherein said step of partially coating said catalytically active metal surface with a eutectic metal salt composition or a precursor thereof provides an improved in situ operation and / or in operando life-time by providing at least one or more of: a. decreased rate of deactivation; b. decreased rate of coke and / or carbon deposition; c. decreased amount of coke and / or carbon deposition; d. increased catalytic activity for DRM after 16 hours; and e. formation of only one distinct type of coke deposits on said metal surface, as when compared against a similar heterogenous catalyst not having been subjected to the same step of partially coating said catalytically active metal surface with a eutectic metal salt composition or a precursor thereof.

[0316] 80. The method according to the preceding item, wherein said in operando is heterogenous catalysis.

[0317] 81. The method according to the preceding item, wherein said in operando is heterogenous catalysis of a reaction involving at least carbon dioxide.

[0318] 82. The method according to any one of the preceding items, wherein said ternary eutectic salt is liquid and / or molten during operation.

[0319] 83. The method according to any one of the preceding items, wherein said ternary eutectic carbonate is liquid and / or molten during operation.

[0320] 84. The method according to any one of the preceding items, wherein said ternary eutectic salt reduces and / or inhibits formation of coke deposits during operation, such as by gasification. 85. The method according to any one of the preceding items, wherein said ternary eutectic salt is a catalyst of and / or catalyzes the reverse Bouduard reaction.

[0321] 86. The method according to any one of the preceding items, wherein said ternary eutectic carbonate reduces and / or inhibits formation of coke deposits during operation, such as by gasification.

[0322] 87. The method according to any one of the preceding items, wherein said ternary eutectic carbonate is a catalyst of and / or catalyzes the reverse Bouduard reaction.

[0323] 88. The method according to any one of the preceding items, wherein formation of coke deposits during operation is reduced and / or inhibited for at least 20 hours of operation, such as at least 100 hours of operation.

[0324] 89. The method according to any one of the preceding items, wherein there is no formation of coke and / or carbonaceous deposits above 600 °C.

[0325] Method of manufacture

[0326] 90. A method for producing the catalyst of any one of items 1 to 57 comprising the steps: a. Providing a porous oxide support; b. Impregnating a solution comprising at least one transition metal into said oxide support to prepare a transition metal impregnated support; c. Drying and calcining said transition metal impregnated support to provide a calcined transition metal impregnated support; d. Impregnating a solution comprising at least three distinct alkali metals into said calcined transition metal impregnated support to provide an alkali impregnated support; e. Drying and calcining said alkali impregnated support to obtain a catalyst precursor, optionally wherein said calcination is performed under a gaseous flow comprising ambient air or air comprising at least an amount of carbon dioxide; f. Reducing said catalyst precursor at a temperature above room temperature in presence of at least hydrogen gas to obtain the catalyst of any one of items 1 to 57.

[0327] Items 2

[0328] 1 . A catalyst composition comprising: a. a porous solid support, b. at least one catalytically active metal, and c. a eutectic metal salt composition or a precursor thereof, said eutectic metal salt composition comprising at least a ternary eutectic salt, optionally wherein said ternary eutectic salt is selected from ternary eutectic carbonate, ternary eutectic formate, ternary eutectic hydroxide, ternary eutectic nitrate and ternary eutectic chloride, or a mixture thereof, further wherein the eutectic metal salt composition is present in an amount corresponding to from 0.5 to 5 % of the total available porous support pore volume and / or is present in an amount corresponding to from 0.5 to 5 wt% of the total catalyst weight.

[0329] 2. The catalyst according to the preceding item, wherein said catalyst composition is suitable for catalyzing the production of syngas from a feed mixture comprising at least methane and carbon dioxide, such as in dry reforming of methane (DRM).

[0330] 3. The catalyst according to any one of the preceding items, wherein the ternary eutectic salt is ternary eutectic carbonate or a ternary eutectic salt composition suitable for being transformed into the corresponding carbonate upon exposure to gaseous carbon dioxide, such as ternary eutectic formate, ternary eutectic hydroxide, ternary eutectic nitrate and ternary eutectic chloride, or a mixture thereof.

[0331] 4. The catalyst according to any one of the preceding items, wherein the ternary eutectic salt comprise U2CO3, Na2COs and K2CO3 in an amount corresponding to 1 :1 :1 by weight of the eutectic composition and is characterized by a melting point in the range of 397 °C to 410 °C.

[0332] 5. The catalyst according to any one of the preceding items, wherein said solid support is a ceramic support selected from ZrC>2, CeC>2, MgAhOt and mixtures thereof. 6. The catalyst according to any one of the preceding items, wherein the catalyst support is characterized by one or more of the following: a. a surface area of 100-150 m2 / g as determined by Brunauer-Emmett- Teller (BET) analysis; and / or b. a total pore volume (Vtot) of 0.1 to 0.5 cm3 / g; and / or c. an average pore diameter (davg) of 3 to 10 nm determined by Barret- Joyner-Halenda (BJH) analysis.

[0333] 7. The catalyst according to any one of the preceding items, wherein the catalytically active metal is Ni and is present in an amount corresponding to 5 % by weight of the porous solid support.

[0334] 8. A method for catalytically producing syngas from a feed mixture comprising at least methane and carbon dioxide, said method making use of the catalyst composition of any one of items 1 to 7 and comprising a step of contacting the feed mixture comprising at least methane and carbon dioxide with the catalyst composition at a temperature above 400 °C, so as to provide that said ternary eutectic salt is liquid and / or molten during operation.

[0335] 9. The method according to item 8, further comprising a pre-treatment step of reducing the catalyst composition of any one of items 1 to 7 at a temperature higher than room temperature prior to the step of contacting the feed mixture comprising at least methane and carbon dioxide with the catalyst composition.

[0336] 10. The method according to any one of items 8 to 9, wherein said syngas is catalytically produced via dry reforming of methane (DRM).

[0337] 11. The method according to any one of items 8 to 10, wherein said catalyst composition inhibits and / or reduces formation of coke deposits during operation.

[0338] 12. A method of improving operando life-time of a heterogenous catalyst comprising a catalytically active metal having at least one catalytically active metal surface, wherein said metal surface is prone to catalysis deactivation by coke formation and / or deposition on said metal surface, the method comprising at least partially coating said catalytically active metal surface with a eutectic metal salt composition or a precursor thereof, said eutectic metal salt composition comprising at least a ternary eutectic salt, optionally wherein said ternary eutectic salt is selected from alkali metal ternary eutectic carbonate, alkali metal ternary eutectic formate, alkali metal ternary eutectic hydroxide, alkali metal ternary eutectic nitrate and alkali metal ternary eutectic chloride, or a mixture thereof.

[0339] 13. The method according to any item 12, wherein said step of partially coating said catalytically active metal surface with a eutectic metal salt composition or a precursor thereof provides an improved operando life-time in dry reforming of methane (DRM) by providing at least one or more of: a. decreased rate of deactivation; b. decreased rate of coke and / or carbon deposition; c. decreased amount of coke and / or carbon deposition; d. increased catalytic activity for DRM after 16 hours of continuous operation; and e. formation of only one distinct type of coke deposits on said metal surface, as when compared against a similar heterogenous catalyst not having been subjected to the same step of partially coating said catalytically active metal surface with a eutectic metal salt composition or a precursor thereof.

[0340] 14. The method according to any one of items 8 to 13, wherein formation of coke deposits during operation is reduced and / or inhibited for at least 20 to 100 hours of continuous operation, and / or wherein there is no formation of coke and / or carbonaceous deposits above 600 °C.

[0341] 15. Use of a catalyst obtained by a manufacturing method comprising the steps: a. Providing a porous oxide support; b. Impregnating a solution comprising at least one transition metal into said oxide support to prepare a transition metal impregnated support; c. Drying and calcining said transition metal impregnated support to provide a calcined transition metal impregnated support; d. Impregnating a solution comprising at least three distinct alkali metals in the form of the formate, carbonate or nitrate, into said calcined transition metal impregnated support to provide an alkali impregnated support; e. Drying and calcining said alkali impregnated support to obtain a catalyst precursor, optionally wherein said calcination is performed under a gaseous flow comprising ambient air or air comprising at least an amount of carbon dioxide; and f. Reducing said catalyst precursor at a temperature above room temperature in presence of at least hydrogen gas to obtain the catalyst; for catalytically producing syngas from a feed mixture comprising at least methane and carbon dioxide.

Claims

Claims1. A catalyst composition comprising: a. a porous solid support having a BET surface area of 50 to 250 m2 / , b. at least one transition metal selected from Ni, Co, Fe, Ru, Rh, Cu, Co, or a binary or ternary mixture thereof, and c. a eutectic metal salt composition or a precursor thereof, said eutectic metal salt composition comprising at least a ternary eutectic salt, optionally wherein said ternary eutectic salt is selected from ternary eutectic carbonate, ternary eutectic formate, ternary eutectic hydroxide, ternary eutectic nitrate and ternary eutectic chloride, or a mixture thereof, further wherein the eutectic metal salt composition is present in an amount corresponding to 0.1 to 20 % by weight of the catalyst composition.

2. The catalyst composition according to any one of the preceding claims, wherein the catalyst is a catalyst composite.

3. The catalyst composition according to any one of the preceding claims, wherein the eutectic metal salt composition optionally further comprises one or more of a second salt.

4. The catalyst composition according to any one of the preceding claims, wherein the one or more second salt is selected from the group consisting of alkali metal salt, earth-alkali metal salt, p-block metal salt, d-block metal salt and f-block metal salt.

5. The catalyst composition according to any one of the preceding claims, wherein the ternary eutectic salt, such as ternary eutectic carbonate, ternary eutectic formate, ternary eutectic hydroxide, ternary eutectic nitrate and ternary eutectic chloride, or a mixture thereof is an alkali metal or alkaline earth metal ternary eutectic salt.

6. The catalyst composition according to any one of the preceding claims, wherein the ternary eutectic salt is ternary eutectic carbonate.

7. The catalyst composition according to any one of claims 1 to 6, wherein the ternary eutectic carbonate is comprised of three distinct carbonate salts individually selected from U2CO3, Na2COs, K2CO3, Rb2CO3, CS2CO3, MgCCh, CaCCh, SrCOs, and BaCCh, or a hydrate thereof, or wherein the ternary eutectic formate comprises at least three formate salts individually selected from Li(O2CH), Na(O2CH), K(O2CH), Rb(O2CH), Cs(O2CH), Mg(O2CH)2, Ca(O2CH)2, Sr(C>2CH)2, and Ba(C>2CH)2, or a hydrate thereof, or wherein the ternary eutectic hydroxide comprises at least three hydroxide salts individually selected from LiOH, NaOH, KOH, RbOH. CsOH, Mg(OH)2, Ca(OH)2, Sr(OH)2, and Ba(OH)2, or a hydrate thereof, or wherein the ternary eutectic nitrate comprises at least three nitrate salts individually selected from UNO3, NaNOs, KNO3, RbNOs, CsNOs, Mg(NO3)2, Ca(NO3)2, Sr(NOs)2, and Ba(NOs)2, or a hydrate thereof, or wherein the ternary eutectic chloride comprises at least three chloride salts individually selected from LiCI, NaCI, KOI, RbCI, CsCI, MgCh, CaCh, SrCh, and BaCh, or a hydrate thereof.

8. The catalyst composition according to any one of the preceding claims, wherein the ternary eutectic salt comprise U2CO3, Na2COs and K2CO3 in an amount corresponding to 1 : 1 : 1 by weight of the eutectic composition.

9. The catalyst composition according to any one of the preceding claims, wherein the ternary eutectic salt comprise 33 (±2) wt% U2CO3; 33 (±2) wt% K2CO3; 33 (±2) wt% Na2CC>3 by weight of the eutectic composition.

10. The catalyst composition according to any one of the preceding claims, wherein the ternary eutectic salt has a melting point in the range of 390 °C to 600 °C, such as 390 °C to 400 °C, such as 400 °C to 450 °C, such as 450 °C to 500 °C, such as 500 °C to 550 °C, such as 550 °C to 600 °C.11 . The catalyst composition according to any one of the preceding claims, wherein the ternary eutectic salt has a melting point in the range of 397 °C to 410 °C.

12. The catalyst composition according to any one of the preceding claims, wherein the ternary eutectic salt is present in an amount corresponding to from 0.1 to 10 wt% of the total catalyst weight, such as from 0.1 to 1.0 wt%, such as from 1.0to 2.0 wt%, such as from 2.0 to 3.0 wt%, such as from 3.0 to 4.0 wt%, such as from 4.0 to 5.0 wt%, such as from 5.0 to 7.0 wt%, such as from 7.0 to 10 wt%.

13. The catalyst composition according to any one of the preceding claims, wherein the ternary eutectic salt is present in an amount corresponding to from 0.5 to 5 wt% of the total catalyst weight, such as 0.5 wt%, 1 .0 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%, 3.0 wt%, 3.5 wt%, 4.0 wt%, 4.5 wt% or 5.0 wt%.

14. The catalyst composition according to any one of the preceding claims, wherein said porous solid support is a ceramic support, such as oxides and / or nitrides and / or carbonates and / or chlorides of one or more metals including mixtures thereof.

15. The catalyst composition according to claim 14, wherein said ceramic support is selected from ZrC>2, CeC>2, AI2O3, TiC>2, SiC>2, CaO, K2O, MgCh, SisN4, MgAhOt, BaO, SrTiOs, La2Os, MgO, CaTiCh, BaTiCh and zeolites such as GME, FAU, ANA, MOR, HEU, LTA, and MFI zeolite types, and mixtures thereof.

16. The catalyst composition according to any one of claims 14 to 15, wherein said ceramic support is selected from ZrO2, CeO2, MgAhO4, AI2O3 and mixtures thereof.

17. The catalyst composition according to any one of claims 14 to 16, further comprising at least one doping ion and / or metal which increases the thermal stability of the support.

18. The catalyst composition according to any one of claims 14 to 17, further comprising at least one doping ion and / or metal optionally, wherein said doping ion and / or metal increases the number of oxygen vacancies in the support.

19. The catalyst composition according to any one of claims 17 to 18, wherein the at least one doping ion and / or metal is yttrium, lanthanum, silicon, magnesium, calcium.

20. The catalyst composition according to any one of claims 17 to 19, wherein the at least one doping ion and / or metal is yttrium.

21. The catalyst composition according to any one of the preceding claims, wherein the porous solid support has a BET surface area of 50-150 m2 / g, such as 50- 100 m2 / g, such as 100-150 m2 / g, as determined by Brunauer-Emmett-Teller (BET) analysis.

22. The catalyst composition according to any one of the preceding claims, wherein the porous solid support has a total pore volume (Vtot) of 0.1 to 0.5 cm3 / g measured by N2-physisorption.

23. The catalyst composition according to any one of the preceding claims, wherein the porous solid support has an average pore diameter (davg) of 3 to 30 nm determined by Barret-Joyner-Halenda (BJH) analysis.

24. The catalyst composition according to any one of the preceding claims, wherein the at least one transition metal is present in the catalyst composition in an amount corresponding to from 1 to 20 % by weight of the total weight of porous solid support and eutectic metal salt composition.

25. The catalyst composition according to any one of the preceding claims, wherein the at least one transition metal is present in the catalyst composition in an amount corresponding to from 2 to 6 % by weight of the total weight of porous solid support and eutectic metal salt composition.

26. The catalyst composition according to any one of the preceding claims, wherein the at least one transition metal is present in the catalyst composition in an amount corresponding to 4 to 5 % by weight of the total weight of porous solid support and eutectic metal salt composition.

27. The catalyst composition according to any one of the preceding claims, wherein the transition metal is Ni and is present in an amount corresponding to 5 % by weight of the porous solid support.

28. The catalyst composition according to any one of the preceding claims, wherein the transition metal is present in the catalyst composition in the form of nanoparticles, such as discrete nanoparticles, having a diameter and / or size between 1-20 nm, such as 10-15 nm, such as 1-10 nm, such as 2-9 nm, such as 3-8 nm, such as 4-7 nm, such as 5-6 nm.

29. The catalyst composition according to any one of the preceding claims, wherein the transition metal is present in the catalyst composition in the form of nanoparticles, such as discrete nanoparticles, having an average diameter and / or size between 1-20 nm, such as 10-15 nm, such as 1-10 nm, such as2-9 nm, such as 3-8 nm, such as 4-7 nm, such as 5-6 nm.

30. The catalyst composition according to any one of the preceding claims, wherein the transition metal size distribution is characterized by a Dso between 1 nm to 20 nm, such as an integer between 10-15 nm, such as an integer between 1-10 nm, such as an integer between 2 nm to 9 nm, such as an integer between 3 nm to 8 nm, such as an integer between 4 nm to 7 nm, such as an integer between 5 nm to 6 nm.

31. The catalyst composition according to any one of the preceding claims, wherein the transition metal size distribution is characterized by a Dso of less than 20 nm, such as 17 nm or less, such as 15 nm or less, such as 12 nm or less, such as 10 nm or less.

32. The catalyst composition according to any one of the preceding claims, wherein the transition metal size distribution is characterized by a D90 between 10 nm to 40 nm, such as an integer between 10 nm and 12 nm, such as an integer between 12 nm and 14 nm, such as an integer between 14 nm and 16 nm, such as an integer between 16 nm and 18 nm, such as an integer between 18 nm and 20 nm, such as an integer between 20 nm and 25 nm, such as an integer between 25 nm and 30 nm, such as an integer between 30 nm and 35 nm, such as an integer between 35 nm and 40 nm.

33. The catalyst composition according to any one of the preceding claims, wherein the transition metal size distribution is characterized by a D90 of less than 20nm, such as 17 nm or less, such as 15 nm or less, such as 12 nm or less, such as 10 nm or less.

34. The catalyst composition according to any one of the preceding claims, wherein said catalyst composition is suitable for catalyzing the production of syngas from a feed mixture comprising at least methane and carbon dioxide, such as in dry reforming of methane (DRM).

35. A method for catalytically producing syngas from a feed mixture comprising at least methane and carbon dioxide, said method making use of the catalyst composition of any one of claims 1 to 34.

36. The method according to claim 37, comprising a step of contacting the feed mixture comprising at least methane and carbon dioxide with the catalyst composition of any one of claims 1 to 34.

37. The method according to any one of the preceding claims, wherein the production of syngas is performed at a temperature of 400 to 800 °C.

38. The method according to any one of claims 35 to 37, wherein the CH4 / CO2 volumetric ratio is 1 :1 in the feed mixture.

39. The method according to any one of claims 35 to 38, wherein the catalyst composition is provided as a particle fraction having a particle size between 180 pm and 355 pm.

40. The method according to any one of claims 35 to 39, further comprising a pretreatment step of reducing the catalyst composition of any one of claims 1 to 35 at a temperature higher than room temperature prior to the step of contacting the feed mixture comprising at least methane and carbon dioxide with the catalyst composition.

41. The method according to claim 40, wherein the pre-treatment step comprise heating the catalyst composition to a temperature of 700-800 °C at a heating ramp of 0.5-20 °C / min in a gas composition of 1-20 ml / min H2 and 20-100ml / min N2, thereby reducing any metal oxides to catalytically active metal nanoparticles.

42. The method according to any one of claims 35 to 41 , wherein said syngas is catalytically produced via dry reforming of methane (DRM).

43. The method according to any one of the preceding claims 35 to 42, wherein said produced syngas comprise a mixture of CO and H2 in a ratio from 1 :2 at a temperature of 650 °C to 1 : 1 at a temperature of 750 °C.

44. The method according to any one of claims 35 to 43, wherein said catalyst composition inhibits formation of coke deposits during operation.

45. The method according to any one of claims 35 to 43, wherein said catalyst composition reduces coke deposits during operation, such as by oxidation and / or gasification.

46. The method according to any one of claims 35 to 45, wherein said ternary eutectic salt is liquid and / or molten during operation.

47. The method according to any one of claims 35 to 46, wherein said method comprise gasification of coke depositions.

48. The method according to any one of claims 35 to 47, wherein said catalyst catalyzes or is capable of catalyzing the reverse Bouduard reaction.

49. The method according to any one of claims 35 to 48, wherein said ternary eutectic salt is a catalyst of and / or catalyzes the reverse Bouduard reaction.

50. The method according to any one of claims 35 to 49, wherein formation of coke deposits during operation is reduced and / or inhibited for at least 20 hours of operation, such as at least 100 hours of operation.51 . A method for producing the catalyst of any one of claims 1 to 34 comprising the steps:a. Providing a porous oxide support, such as having a BET surface area of 50 to 250 m2 / g; b. Impregnating a solution comprising at least one transition metal into said oxide support to prepare a transition metal impregnated support; c. Drying and calcining said transition metal impregnated support to provide a calcined transition metal impregnated support; d. Impregnating a solution comprising at least three distinct alkali metals into said calcined transition metal impregnated support to provide an alkali impregnated support; e. Drying and calcining said alkali impregnated support to obtain a calcinated catalyst, optionally wherein said calcination is performed under a gaseous flow comprising ambient air or air comprising at least an amount of carbon dioxide; f. Reducing said calcinated catalyst at a temperature above room temperature in presence of at least hydrogen gas to obtain the catalyst of any one of claims 1 to 34.

52. The method according to claim 51 , wherein said solution comprising at least three distinct alkali metals of step d is provided as the formate, nitrate, carbonate, hydroxide or halide salt of said alkali metals.

53. The method according to any one of claims 51 to 52, wherein said the three distinct alkali metals of step d are Li, Na and K and are preferably provided as their salts in a weight ratio of 1 : 1 : 1 in the solution of step d.

54. The method according to any one of claims 51 to 53, wherein said solution comprising at least three distinct alkali metals of step d is provided in an amount corresponding to a final ternary eutectic salt loading of from 0.1 to 20 wt% of the total catalyst weight.

55. The method according to any one of claims 51 to 54, wherein the at least one transition metal is selected from Ni, Co, Fe, Ru, Rh, Cu, Co, or a binary or ternary mixture thereof.

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