Ni-based catalyst for NH3 reforming applications

Abstract

The present invention relates to a catalyst comprising Ni, Ru and an accelerator metal M1 wherein the catalyst shows a Ru: Ni weight ratio in the range of 0.0001: 1 to 0.5: 1 wherein the accelerator metal M1 is selected from the group consisting of Li, K, Na, Cs, Mg, Ca, Sr and Ba, including mixtures of two or more thereof, and wherein the catalyst further comprises one or more support materials on which Ni, Ru and the accelerator metal M1 are supported, respectively. Furthermore, the invention relates to a process for preparing a catalyst comprising Ni, Ru and an accelerator metal M1, as well as to a catalyst obtainable according to said process, and to a process for reforming ammonia using the catalyst according to the invention.

Description

Technical Field

[0001] The present invention relates to a catalyst for reforming ammonia, and a method for producing the catalyst, and a method for reforming ammonia using the catalyst. Background Art

[0002] NH3 is seen as a future energy carrier, capable of storing chemically large amounts of H2. Therefore, sustainable NH3 could potentially be produced on a large scale from renewable energy sources. Reforming NH3 on-site where H2 is required (see equation 1 below) could be the final step to complete the H2 value chain based on renewable electricity.

[0003] (1)

[0004] I. Lucentini et al., Ind. Eng. Chem. Res. [Industrial and Engineering Chemistry Research] 2021, 60, pp. 18560-18611 and T. Le et al., Korean J. Chem. Eng. [Korean Journal of Chemical Engineering], 2021, 38(6), pp. 1087-1103, respectively provide an overview of catalysts used in ammonia decomposition.

[0005] X.-K. Li et al., Journal of Catalysis, 2005, 236, pp. 181-189, specifically relate to the decomposition of ammonia over Ni and Ru catalysts.

[0006] Bell et al., Top Catal. [Journal of Catalysis Topics], 2016, 59, pp. 1438-1457, relates to the use of non-precious metal catalysts for ammonia decomposition, wherein Co- and Ni-containing catalysts are mainly discussed.

[0007] Although a large number of catalysts for ammonia decomposition have been developed, there remains a need for still more efficient catalysts. In particular, there remains a need for catalysts that can convert ammonia into hydrogen and nitrogen at low temperatures, thereby allowing for efficient processes for ammonia decomposition. DETAILED DESCRIPTION

[0008] Thus, it has been unexpectedly found that the use of relatively low amounts of Ru in Ni-based catalysts promoted with K provides unexpectedly high conversions at low temperatures when used for the decomposition of ammonia. In particular, a very strong synergistic effect between Ru, Ni and K in the catalytic decomposition of ammonia has been found quite unexpectedly, wherein only small amounts of Ru are required to obtain an efficient catalyst.

[0009] Accordingly, the present invention relates to a catalyst comprising Ni, Ru and a promoter metal M1, wherein the catalyst shows a Ru:Ni weight ratio in the range of 0.0001:1 to 0.5:1, wherein the promoter metal M1 is selected from the group consisting of: Li, K, Na, Cs, Mg, Ca, Sr and Ba, including mixtures of two or more thereof, and wherein the catalyst further comprises one or more support materials on which Ni, Ru and the promoter metal M1 are respectively supported.

[0010] Preferably, the catalyst shows a Ru:Ni weight ratio in the range of 0.001:1 to 0.9:1, more preferably 0.005:1 to 0.5:1, more preferably 0.01:1 to 0.1:1, more preferably 0.02:1 to 0.05:1, and more preferably 0.025:1 to 0.035:1.

[0011] Preferably, the promoter metal M1 is selected from the group consisting of: Li, K, Na, Cs, Mg and Ca, including mixtures of two or more thereof, more preferably selected from the group consisting of: Li, K, Na and Cs, including mixtures of two or more thereof, more preferably selected from the group consisting of: Li, K and Na, including mixtures of two or more thereof, wherein more preferably the promoter metal M1 is Li, K, or Li and K, wherein more preferably the promoter metal M1 is K, wherein more preferably the promoter metal M1 consists of Li, K, or Li and K, wherein more preferably the promoter metal M1 consists of K.

[0012] Preferably, the catalyst shows a Ni:M1 atomic ratio in the range of 0.1:1 to 30:1, more preferably 0.5:1 to 20:1, more preferably 1:1 to 15:1, more preferably 1.5:1 to 10:1, more preferably 2:1 to 6:1, more preferably 2.5:1 to 4:1, more preferably 2.7:1 to 3.5:1, and more preferably 2.9:1 to 3:1.

[0013] Preferably, the one or more support materials are selected from the group consisting of metal oxides, wherein the metals of these metal oxides are more preferably selected from the group consisting of: Al, Si, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, alkaline earth metals and rare earth metals, including combinations of two or more thereof, more preferably selected from the group consisting of: Al, Si, Ti, Zr, Mg, Ca, La, Ce, Pr and Nd, including combinations of two or more thereof, more preferably selected from the group consisting of: Al, Ti, Zr, Mg, Ca and La, including combinations of two or more thereof, and more preferably selected from the group consisting of: Al, Zr and Mg, including combinations of two or more thereof, wherein more preferably Preferably, the one or more support materials comprise one or more metal oxides selected from the group consisting of Al2O3, ZrO2 and spinel, including mixtures of two or more thereof, preferably selected from the group consisting of ZrO2 and spinel, including mixtures of two or more thereof, more preferably selected from the group consisting of ZrO2, NiMgO2 and MgAl2O4, including mixtures of two or more thereof, wherein more preferably, the one or more support materials comprise MgAl2O4, preferably NiMgO2 and MgAl2O4, wherein more preferably, the one or more support materials consist of MgAl2O4, or NiMgO2 and MgAl2O4, preferably NiMgO2 and MgAl2O4.

[0014] Preferably, 90 to 100 wt.-%, more preferably 95 to 100 wt.-%, more preferably 99 to 100 wt.-%, more preferably 99.5 to 100 wt.-%, and more preferably 99.9 to 100 wt.-% of Ni and Ru, calculated as the respective elements and based on 100 wt.-% of Ni and Ru contained in the catalyst, are supported on one or more support materials contained in the catalyst.

[0015] Preferably, 90 to 100 wt.-%, more preferably 95 to 100 wt.-%, more preferably 99 to 100 wt.-%, more preferably 99.5 to 100 wt.-%, and more preferably 99.9 to 100 wt.-% of the Ni, Ru and the promoter metal M1, calculated as the respective elements and based on 100 wt.-% of the Ni, Ru and the promoter metal M1 contained in the catalyst, are supported on one or more support materials contained in the catalyst.

[0016] Preferably, the catalyst comprises Ni in an amount in the range of 1 to 75 wt.-%, more preferably 3 to 60 wt.-%, more preferably 5 to 40 wt.-%, more preferably 10 to 25 wt.-%, more preferably 12 to 18 wt.-%, and more preferably 14 to 16 wt.-%, calculated as element and based on 100 wt.-% of the catalyst.

[0017] Preferably, the catalyst comprises Ru in an amount in the range of 0.01 to 5 wt.-%, more preferably 0.05 to 2.5 wt.-%, more preferably 0.1 to 1.5 wt.-%, more preferably 0.2 to 1 wt.-%, more preferably 0.3 to 0.8 wt.-%, and more preferably 0.4 to 0.6 wt.-%, calculated as the element and based on 100 wt.-% of the catalyst.

[0018] Preferably, the catalyst comprises the promoter metal M1 in an amount in the range of 0.05 to 25 wt.-%, more preferably 0.1 to 15 wt.-%, more preferably 0.5 to 10 wt.-%, more preferably 1 to 8 wt.-%, more preferably 2 to 5 wt.-%, and more preferably 3 to 4 wt.-%, calculated as element and based on 100 wt.-% of the catalyst.

[0019] Preferably, 95 to 100 wt.-%, more preferably 97 to 100 wt.-%, more preferably 98 to 100 wt.-%, more preferably 99 to 100 wt.-%, more preferably 99.5 to 100 wt.-%, and more preferably 99.9 to 100 wt.-% of the catalyst consists of Ni, Ru, the promoter metal M1 and one or more support materials, wherein Ni, Ru and the promoter metal M1 may be present as elements, oxides and / or salts, respectively.

[0020] Preferably, the catalyst comprises one or more promoter metals M1 as hydroxides, bicarbonates and / or carbonates, more preferably as hydroxides and / or bicarbonates, and more preferably as hydroxides, wherein more preferably the promoter metal M1 is contained in the catalyst as its hydroxide salt.

[0021] Preferably, Ru is loaded on one or more support materials by impregnation technique using an aqueous solution of one or more ruthenium salts, wherein the one or more ruthenium salts more preferably include Ru(NO)(NO3)3, wherein Ru(NO)(NO3)3 is more preferably used as the one or more ruthenium salts.

[0022] Preferably, the catalyst is in the form of a molding, in the form of an extrudate, and / or in the form of a powder, more preferably in the form of a molding or an extrudate, and more preferably in the form of a molding.

[0023] Where the catalyst is in the form of extrudates, it is preferred that the extrudates have a diameter in the range of 0.5 to 10 mm, more preferably 1 to 7 mm, more preferably 1.5 to 5 mm, more preferably 2 to 4 mm, and more preferably 2.5 to 3.5 mm.

[0024] In the case where the catalyst is in the form of moldings, it is preferred that these moldings have a diameter in the range from 1 to 20 mm, more preferably in the range from 1 to 15 mm.

[0025] In the case where the catalyst is in the form of a molding, it is preferred that the molding has a four-leaf shape. Within the meaning of the present patent application, the term four-leaf preferably refers to a catalyst as in WO 2020 / 157202 A1 Figure 1 The geometric shapes depicted in .

[0026] The present invention also relates to a method for preparing a catalyst comprising Ni, Ru and a promoter metal M1 (preferably a catalyst comprising Ni, Ru and a promoter metal M1 according to any one of the specific and preferred embodiments of the present invention), the method comprising

[0027] (1) preparing a mixture comprising one or more Ni sources, one or more support materials and / or one or more precursors thereof, and water;

[0028] (2) forming the mixture obtained in (1);

[0029] (3) calcining the molded body obtained in (2);

[0030] (4) impregnating the calcined body obtained in (3) with an aqueous solution of one or more Ru salts;

[0031] (5) calcining the impregnated molded body obtained in (4);

[0032] (6) impregnating the calcined shaped body obtained in (5) with an aqueous solution of one or more salts of a promoter metal M1, wherein the promoter metal M1 is selected from the group consisting of Li, K, Na, Cs, Mg, Ca, Sr and Ba, including mixtures of two or more thereof;

[0033] (7) Calcination of the impregnated molded body obtained in (6).

[0034] Preferably, in (1), the one or more Ni sources comprise one or more Ni salts, wherein the anions of the one or more Ni salts are more preferably selected from the group consisting of halides, carbonates, bicarbonates, sulfates, bisulfates, hydroxides, nitrates, phosphates, hydrogen phosphates, dihydrogen phosphates, acetates, and combinations of two or more thereof,

[0035] More preferably selected from the group consisting of chloride, bromide, fluoride, bicarbonate, bisulfate, nitrate, dihydrogen phosphate, acetate, and combinations of two or more thereof,

[0036] More preferably selected from the group consisting of chloride, fluoride, nitrate, acetate and combinations of two or more thereof,

[0037] Wherein more preferably, the anion of the one or more Ni salts is chloride and / or nitrate, preferably nitrate,

[0038] And wherein more preferably, the one or more Ni sources include nickel (II) nitrate, wherein more preferably, the one or more Ni sources are nickel (II) nitrate.

[0039] In case the one or more Ni sources comprise one or more Ni salts in (1), it is preferred that the one or more Ni sources are provided as an aqueous solution of the one or more nickel salts.

[0040] Preferably, in (1), the one or more support materials are selected from the group consisting of metal oxides, wherein the metals of the metal oxides are more preferably selected from the group consisting of Al, Si, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, alkaline earth metals and rare earth metals, including combinations of two or more thereof, more preferably selected from the group consisting of Al, Si, Ti, Zr, Mg, Ca, La, Ce, Pr and Nd, including combinations of two or more thereof, more preferably selected from the group consisting of Al, Ti, Zr, Mg, Ca and La, including combinations of two or more thereof, and more preferably selected from the group consisting of Al, Zr and Mg, including combinations of two or more thereof. More preferably, the one or more support materials comprise one or more metal oxides selected from the group consisting of Al2O3, ZrO2 and spinel, including mixtures of two or more thereof, preferably selected from the group consisting of ZrO2 and spinel, including mixtures of two or more thereof, more preferably selected from the group consisting of ZrO2, NiMgO2 and MgAl2O4, including mixtures of two or more thereof, wherein more preferably, the one or more support materials comprise MgAl2O4, preferably NiMgO2 and MgAl2O4, wherein more preferably, the one or more support materials consist of MgAl2O4, or NiMgO2 and MgAl2O4, preferably NiMgO2 and MgAl2O4.

[0041] Preferably, in (1), the one or more precursors of the one or more support materials comprise hydrotalcite, wherein more preferably, the one or more precursors of the one or more support materials are hydrotalcite.

[0042] Preferably, (1) comprises preparing a mixture comprising one or more Ni sources, one or more precursors of one or more support materials, and water, wherein more preferably, (1) consists of preparing a mixture comprising one or more Ni sources, one or more precursors of one or more support materials, and water.

[0043] Preferably, in (2), shaping is achieved by molding or extruding the mixture obtained in (1), more preferably by extrusion.

[0044] Preferably, the calcination in (3) is performed at a temperature ranging from 500°C to 1,150°C, more preferably from 700°C to 1,100°C, more preferably from 850°C to 1,050°C, and more preferably from 950°C to 1,050°C.

[0045] Preferably, the calcination in (3) is carried out for a duration ranging from 0.5 to 9 h, more preferably from 1.5 to 6 h, and more preferably from 2 to 3 h.

[0046] Preferably, in (4), the anion of the one or more Ru salts is selected from the group consisting of halide, carbonate, bicarbonate, sulfate, bisulfate, hydroxide, nitrate, phosphate, hydrogen phosphate, dihydrogen phosphate, acetate, and a combination of two or more thereof,

[0047] More preferably selected from the group consisting of chloride, bromide, fluoride, bicarbonate, bisulfate, nitrate, dihydrogen phosphate, acetate, and combinations of two or more thereof,

[0048] More preferably selected from the group consisting of chloride, fluoride, nitrate, acetate and combinations of two or more thereof,

[0049] Wherein more preferably, the anion of the one or more Ru salts is chloride and / or nitrate, preferably nitrate,

[0050] And wherein more preferably, the one or more Ru salts include Ru(NO)(NO3)3, wherein more preferably, the one or more Ru salts are Ru(NO)(NO3)3.

[0051] Preferably, independently of each other, the impregnation in (4) and (6) is achieved by incipient wetness impregnation.

[0052] It is preferred that the calcinations in (5) and (7) are carried out, independently of each other, at a temperature ranging from 100 to 800°C, more preferably from 350 to 700°C, more preferably from 400 to 600°C, and more preferably from 450 to 550°C.

[0053] It is preferred that, independently of each other, the calcinations in (5) and (7) are carried out for a duration ranging from 1 to 9 h, more preferably from 1.5 to 6 h, and more preferably from 2 to 3 h.

[0054] Preferably, in (6), the promoter metal M1 is selected from the group consisting of Li, K, Na, Cs, Mg and Ca, including mixtures of two or more thereof, preferably selected from the group consisting of Li, K, Na and Cs, including mixtures of two or more thereof, more preferably selected from the group consisting of Li, K and Na, including mixtures of two or more thereof, wherein more preferably the promoter metal M1 is Li, K, or Li and K, wherein more preferably the promoter metal M1 is K, wherein more preferably the promoter metal M1 consists of Li, K, or Li and K, wherein more preferably the promoter metal M1 consists of K.

[0055] Preferably, in (6), the one or more salts of the promoter metal M1 are selected from the group consisting of hydroxides, bicarbonates and carbonates, including mixtures of two or more thereof, wherein more preferably, the one or more salts of the promoter metal M1 are hydroxides and / or bicarbonates, preferably hydroxides, wherein more preferably, in (6), the one or more salts of the promoter metal M1 are hydroxides.

[0056] The present invention also relates to a catalyst comprising Ni, Ru and a promoter metal M1, preferably a catalyst according to any one of the specific and preferred embodiments of the present invention, obtained or obtainable as a method according to any one of the specific and preferred embodiments of the method of the present invention.

[0057] The present invention also relates to a method for reforming ammonia, wherein the method comprises

[0058] (i) providing a reactor containing a catalyst according to any one of the specific and preferred embodiments of the present invention;

[0059] (ii) preparing a feed gas stream comprising NH3;

[0060] (iii) feeding the feed gas stream prepared in (ii) into the reactor provided in (i), and contacting the feed gas stream with the catalyst;

[0061] (iv) removing an effluent gas stream from the reactor, the effluent gas stream comprising H2 and N2.

[0062] Preferably, the contacting in (iii) is carried out at a pressure in the range of 1 to 100 absolute bar, more preferably 10 to 75 absolute bar, more preferably 15 to 40 absolute bar, more preferably 18 to 35 absolute bar, more preferably 20 to 28 absolute bar, and more preferably 20 to 25 absolute bar.

[0063] Preferably, the contacting in (iii) is carried out at a temperature ranging from 300°C to 1,100°C, more preferably from 450°C to 1,000°C, preferably from 500°C to 900°C, more preferably from 500°C to 800°C, more preferably from 500°C to 600°C.

[0064] Preferably, the feed gas stream prepared in (ii) comprises 1 to 100 vol.-%, more preferably 3 to 99.99 vol.-%, more preferably 5 to 99.95 vol.-%, more preferably 10 to 99.9 vol.-%, more preferably 20 to 99.8 vol.-%, more preferably 30 to 99.7 vol.-%, more preferably 40 to 99.6 vol.-%, and more preferably 50 to 99.5 vol.-% NH3.

[0065] Preferably, the feed gas stream prepared in (ii) comprises 0 to 50 vol.-%, more preferably 0.01 to 30 vol.-%, more preferably 0.03 to 15 vol.-%, more preferably 0.05 to 5 vol.-%, more preferably 0.1 to 1 vol.-%, more preferably 0.12 to 0.5 vol.-%, and more preferably 0.14 to 0.16 vol.-% N2.

[0066] Preferably, the feed gas stream prepared in (ii) comprises 0 to 75 vol.-%, more preferably 0 to 60 vol.-%, more preferably 0 to 50 vol.-%, more preferably 0 to 40 vol.-%, more preferably 0 to 35 vol.-%, and more preferably 0 to 30 vol.-% H2.

[0067] Preferably, the feed gas stream prepared in (ii) comprises 100 to 50,000 ppmv, more preferably 200 to 30,000 ppmv, more preferably 500 to 25,000 ppmv, more preferably 1,000 to 20,000 ppmv, more preferably 3,000 to 15,000 ppmv, more preferably 5,000 to 10,000 ppmv H2O.

[0068] Preferably, the total amount of NH3, N2 and H2 contained in the feed gas stream prepared in (ii) is in the range of 90 to 100 wt.-%, preferably 95 to 99.95 vol.-%, more preferably 98 to 99.9 vol.-%, more preferably 99 to 99.85 vol.-%, and more preferably 99.7 to 99.8 vol.-%.

[0069] Preferably, the feed stream is fed at a rate of 500 to 40,000 h -1 , more preferably 700 to 20,000h -1 , more preferably 800 to 16,000h-1 , more preferably 900 to 10,000h -1 , and more preferably 1,000 to 8,000h -1 The gas hourly space velocity in the range is fed into the reactor.

[0070] Preferably, after (i) and before (iii), the catalyst contained in the reactor provided in (i) is reduced in an atmosphere comprising hydrogen and / or NH 3 , more preferably comprising hydrogen.

[0071] In the case where the catalyst contained in the reactor provided in (i) is reduced in an atmosphere comprising hydrogen and / or NH3 after (i) and before (iii), it is preferred that the reduction is carried out at a temperature in the range of 450°C to 1050°C, more preferably 500°C to 950°C, more preferably 600°C to 920°C, more preferably 600°C to 890°C, more preferably 600°C to 870°C, and more preferably 600°C to 700°C.

[0072] In case the catalyst contained in the reactor provided in (i) is reduced in an atmosphere comprising hydrogen and / or NH3 after (i) and before (iii), it is preferred that the reduction is carried out in an atmosphere comprising 1 to 99 vol.-%, more preferably 3 to 90 vol.-%, more preferably 5 to 80 vol.-%, more preferably 6 to 50 vol.-%, more preferably 7 to 30 vol.-%, more preferably 8 to 20 vol.-%, and more preferably 9 to 15 vol-%. In addition and independently of this, it is preferred that the atmosphere comprises 1 to 99 vol.-%, more preferably 5 to 95 vol.-%, more preferably 10 to 90 vol.-%, more preferably 30 to 70 vol.-%, and more preferably 45 to 55 vol.-% of an inert gas.

[0073] In case the atmosphere contains 1 to 99 vol.-% of an inert gas, it is preferred that the inert gas comprises one or more gases selected from the group consisting of rare gases, CO2 and nitrogen, more preferably selected from the group consisting of He, Ar, Ne, N2 and CO2, wherein more preferably the inert gas comprises CO2, N2, or CO2 and N2, wherein more preferably the inert gas comprises N2, wherein more preferably the inert gas is N2.

[0074] According to the present invention, it is preferred that the method of the present invention is used for reforming ammonia and hydrocarbons, wherein the feed gas stream prepared in (ii) further comprises one or more hydrocarbons and one or more of CO2 and H2O, and wherein the effluent gas stream removed in (iv) further comprises CO.

[0075] In case the process of the present invention is used for reforming ammonia and hydrocarbons, it is further preferred that the feed gas stream prepared in (ii) further comprises CO2 and one or more hydrocarbons, and wherein the feed gas stream more preferably comprises 5 vol.-% or less H2O, more preferably 3 vol.-% or less, more preferably 1 vol.-% or less, more preferably 0.5 vol.-% or less, more preferably 0.1 vol.-% or less, more preferably 0.05 vol.-% or less, and more preferably 0.01 vol.-% or less H2O.

[0076] In case the process of the present invention is used for reforming ammonia and hydrocarbons, it is alternatively preferred that the feed gas stream prepared in (ii) further comprises H2O and one or more hydrocarbons, and wherein the feed gas stream preferably comprises 5 vol.-% or less CO2, more preferably 3 vol.-% or less, more preferably 1 vol.-% or less, more preferably 0.5 vol.-% or less, more preferably 0.1 vol.-% or less, more preferably 0.05 vol.-% or less, and more preferably 0.01 vol.-% or less CO2.

[0077] Where the process of the invention is used for reforming ammonia and hydrocarbons, it is further alternatively preferred that the feed gas stream prepared in (ii) further comprises CO2, H2O and one or more hydrocarbons.

[0078] In the case where the process of the present invention is used for reforming ammonia and hydrocarbons, it is preferred that the one or more hydrocarbons are selected from the group consisting of alkanes and mixtures thereof, more preferably C1-C10 alkanes and mixtures thereof, more preferably C3-C9 alkanes and mixtures thereof, more preferably C4-C8 alkanes and mixtures thereof, more preferably C5-C7 alkanes and mixtures thereof, more preferably C6 alkanes and mixtures thereof.

[0079] Additionally and independently thereof, it is preferred that the contacting is carried out at a pressure in the range of greater than 10 to 50 absolute bar, more preferably 12 to 45 absolute bar, more preferably 15 to 40 absolute bar, more preferably 18 to 35 absolute bar, and more preferably 20 to 30 absolute bar.

[0080] Additionally and independently thereof, it is preferred that the feed gas stream prepared in (ii) comprises 0.1 to 75 vol.-%, more preferably 0.3 to 60 vol.-%, more preferably 0.5 to 50 vol.-%, more preferably 0.8 to 40 vol.-%, and more preferably 1 to 30 vol.-% NH3.

[0081] Additionally and independently thereof, it is preferred that the feed gas stream prepared in (ii) comprises 10 to 70 vol.-%, more preferably 12 to 60 vol.-%, and more preferably 15 to 50 vol.-% of the one or more hydrocarbons.

[0082] Additionally and independently thereof, it is preferred that the feed gas stream prepared in (ii) comprises 0 to 75 vol.-%, more preferably 0.5 to 70 vol.-%, more preferably 1 to 68 vol.-%, more preferably 3 to 66 vol.-%, more preferably 5 to 64 vol.-%, more preferably 8 to 62 vol.-%, and more preferably 10 to 60 vol.-% H2O.

[0083] In addition and independently of this, it is preferred that the feed gas stream prepared in (ii) contains 0 to 60 vol.-%, more preferably 1 to 58 vol.-%, more preferably 3 to 56 vol.-%, more preferably 5 to 54 vol.-%, more preferably 8 to 52 vol.-%, and more preferably 10 to 50 vol.-% CO2.

[0084] Additionally and independently thereof, it is preferred that the feed stream shows a H2O:C molar ratio of H2O to carbon contained in the one or more hydrocarbons in the range of 0 to 4, more preferably 0.1 to 3, more preferably 0.3 to 2.5, more preferably 0.4 to 2, and more preferably 0.5 to 1.6.

[0085] Additionally and independently thereof, it is preferred that the feed stream shows a CO2:C molar ratio of CO2 to carbon contained in the one or more hydrocarbons in the range of 0 to 4, more preferably 0.1 to 3, more preferably 0.2 to 2, and more preferably 0.3 to 1.5.

[0086] In addition and independently thereof, it is preferred that the feed stream shows an NH3:C molar ratio of NH3 to carbon contained in the one or more hydrocarbons in the range of 0 to 5, more preferably 0 to 4, more preferably 0.001 to 3, more preferably 0.005 to 2, and more preferably 0.01 to 1.

[0087] Additionally and independently thereof, it is preferred that the feed stream be heated at a rate of 500 to 16,000 h. -1 , more preferably 700 to 14,000h -1 , more preferably 800 to 12,000h -1 , more preferably 900 to 10,000h -1 , and more preferably 1,000 to 8,000h -1 The gas hourly space velocity in the range is fed into the reactor.

[0088] Additionally and independently thereof, it is preferred that the effluent gas stream removed in (iv) further comprises CO2.

[0089] Additionally and independently thereof, it is preferred that the effluent gas stream removed in (iv) shows a stoichiometric number R in the range of 0.1 to 3, wherein R is defined according to formula (I):

[0090]

[0091] Wherein c(H2), c(CO2) and c(CO) represent the molar concentrations of H2, CO2 and CO in the effluent gas stream, respectively. Preferably, the stoichiometric number R is in the range of 1 to 2.5, more preferably 1.3 to 2.2. Alternatively, it is preferred that R>2.

[0092] Additionally and independently thereof, it is preferred that the effluent gas stream removed in (iv) shows a H2:CO molar ratio of >2.

[0093] In cases where the effluent gas stream removed in (iv) shows a H2:CO molar ratio > 2, it is preferred that the stoichiometric number R is in the range of 0.5 to 3, more preferably 1 to 2.2, and more preferably 1.3 to 1.7.

[0094] In case the process of the present invention is used for reforming ammonia and hydrocarbons, it is preferred that the effluent gas stream removed in (iv) contains 10 to 90 vol.-%, more preferably 20 to 80 vol.-%, more preferably 30 to 70 vol.-%, more preferably 40 to 65 vol.-%, and more preferably 45 to 60 vol.-% H2.

[0095] Additionally and independently thereof, it is preferred that the effluent gas stream removed in (iv) comprises 1 to 70 vol.-%, more preferably 3 to 50 vol.-%, more preferably 5 to 40 vol.-%, more preferably 10 to 35 vol.-%, and more preferably 15 to 30 vol.-% CO.

[0096] In addition and independently thereof, it is preferred that the effluent gas stream removed in (iv) contains 1 to 50 vol.-%, more preferably 3 to 45 vol.-%, more preferably 5 to 40 vol.-%, more preferably 8 to 35 vol.-%, more preferably 10 to 30 vol.-%, and more preferably 12 to 25 vol.-% CO2.

[0097] According to the process for reforming ammonia of the present invention, it is preferred that the effluent gas stream removed in (iv) is used in a process for producing methanol, for producing dimethyl ether, or for producing methanol and dimethyl ether.

[0098] Furthermore, it is preferred that the effluent gas stream removed in (iv) is used in a process for producing hydrocarbons, preferably according to the Fischer-Tropsch process.

[0099] Furthermore, it is preferred that the effluent gas stream removed in (iv) is used in a process for producing alcohols, more preferably alkanols, more preferably C1 to C10 alkanols, more preferably C2 to C8 alkanols, more preferably C2 to C6 alkanols, more preferably C2 to C4 alkanols, more preferably C2 alkanols, and more preferably ethanol.

[0100] Furthermore, it is preferred that, in the initial stage of the process, the feed gas stream prepared in (ii) and fed to the reactor in (iii) further comprises H2 for reducing the catalyst. Preferably, the feed gas stream prepared in (ii) and fed to the reactor in (iii) further comprises 0.5 to 80 vol.-%, preferably 1 to 70 vol.-%, more preferably 2 to 60 vol.-%, more preferably 5 to 50 vol.-%, more preferably 15 to 40 vol.-% H2.

[0101] Finally, the present invention also relates to the use of a catalyst comprising Ni, Ru and a promoter metal M1 according to any one of the particular and preferred embodiments of the present invention for the reforming of NH3 to N2 and H2.

[0102] The present invention is further illustrated by the following groups of examples and the combination of examples obtained by the dependencies and back-references as shown. In particular, it should be noted that in each case where a series of examples is mentioned, for example in the context of terms such as "composite oxides as described in any one of Examples 1 to 4", each example in this series is intended to be disclosed clearly to the skilled person, that is, the wording of this term should be understood by the skilled person as synonymous with "composite oxides as described in any one of Examples 1, 2, 3 and 4". In addition, it is explicitly pointed out that the following group of examples is not a group of claims that determines the scope of protection, but represents an appropriate structural part of this specification relating to the general and preferred aspects of the present invention.

[0103] 1. A catalyst comprising Ni, Ru and a promoter metal M1, wherein the catalyst shows a Ru:Ni weight ratio in the range of 0.0001:1 to 0.5:1, wherein the promoter metal M1 is selected from the group consisting of: Li, K, Na, Cs, Mg, Ca, Sr and Ba, including mixtures of two or more thereof, and wherein the catalyst further comprises one or more support materials on which Ni, Ru and the promoter metal M1 are respectively loaded.

[0104] 2. The catalyst of embodiment 1, wherein the catalyst shows a Ru:Ni weight ratio in the range of 0.001:1 to 0.9:1, preferably 0.005:1 to 0.5:1, more preferably 0.01:1 to 0.1:1, more preferably 0.02:1 to 0.05:1, and more preferably 0.025:1 to 0.035:1.

[0105] 3. The catalyst of embodiment 1 or 2, wherein the promoter metal M1 is selected from the group consisting of: Li, K, Na, Cs, Mg and Ca, including mixtures of two or more thereof, preferably selected from the group consisting of: Li, K, Na and Cs, including mixtures of two or more thereof, more preferably selected from the group consisting of: Li, K and Na, including mixtures of two or more thereof, wherein more preferably the promoter metal M1 is Li, K, or Li and K, wherein more preferably the promoter metal M1 is K, wherein more preferably the promoter metal M1 consists of Li, K, or Li and K, wherein more preferably the promoter metal M1 consists of K.

[0106] 4. The catalyst of any one of Embodiments 1 to 3, wherein the catalyst shows a Ni:M1 atomic ratio in the range of 0.1:1 to 30:1, preferably 0.5:1 to 20:1, more preferably 1:1 to 15:1, more preferably 1.5:1 to 10:1, more preferably 2:1 to 6:1, more preferably 2.5:1 to 4:1, more preferably 2.7:1 to 3.5:1, and more preferably 2.9:1 to 3:1.

[0107] 5. The catalyst of any one of embodiments 1 to 4, wherein the one or more support materials are selected from the group consisting of metal oxides, wherein the metals of the metal oxides are preferably selected from the group consisting of Al, Si, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, alkaline earth metals and rare earth metals, including combinations of two or more thereof, more preferably selected from the group consisting of Al, Si, Ti, Zr, Mg, Ca, La, Ce, Pr and Nd, including combinations of two or more thereof, more preferably selected from the group consisting of Al, Ti, Zr, Mg, Ca and La, including combinations of two or more thereof, and more preferably selected from the group consisting of Al, Zr and Mg, including two or more thereof combination, wherein more preferably, the one or more support materials comprise one or more metal oxides selected from the group consisting of: Al2O3, ZrO2 and spinel, including mixtures of two or more thereof, preferably selected from the group consisting of: ZrO2 and spinel, including mixtures of two or more thereof, more preferably selected from the group consisting of: ZrO2, NiMgO2 and MgAl2O4, including mixtures of two or more thereof, wherein more preferably, the one or more support materials comprise MgAl2O4, preferably NiMgO2 and MgAl2O4, wherein more preferably, the one or more support materials consist of MgAl2O4, or NiMgO2 and MgAl2O4, preferably NiMgO2 and MgAl2O4.

[0108] 6. The catalyst of any one of embodiments 1 to 5, wherein 90 to 100 wt.-%, preferably 95 to 100 wt.-%, more preferably 99 to 100 wt.-%, more preferably 99.5 to 100 wt.-%, and more preferably 99.9 to 100 wt.-% of Ni and Ru, calculated as the corresponding elements and based on 100 wt.-% of Ni and Ru contained in the catalyst, are supported on one or more support materials contained in the catalyst.

[0109] 7. The catalyst of any one of embodiments 1 to 6, wherein 90 to 100 wt.-%, preferably 95 to 100 wt.-%, more preferably 99 to 100 wt.-%, more preferably 99.5 to 100 wt.-%, and more preferably 99.9 to 100 wt.-% of Ni, Ru and promoter metal M1, calculated as the corresponding elements and based on 100 wt.-% of Ni, Ru and promoter metal M1 contained in the catalyst, are supported on one or more support materials contained in the catalyst.

[0110] 8. The catalyst of any one of embodiments 1 to 7, wherein the catalyst comprises Ni in an amount ranging from 1 to 75 wt.-%, preferably 3 to 60 wt.-%, more preferably 5 to 40 wt.-%, more preferably 10 to 25 wt.-%, more preferably 12 to 18 wt.-%, and more preferably 14 to 16 wt.-%, calculated as the element and based on 100 wt.-% of the catalyst.

[0111] 9. The catalyst of any one of embodiments 1 to 8, wherein the catalyst comprises Ru in an amount ranging from 0.01 to 5 wt.-%, preferably 0.05 to 2.5 wt.-%, more preferably 0.1 to 1.5 wt.-%, more preferably 0.2 to 1 wt.-%, more preferably 0.3 to 0.8 wt.-%, and more preferably 0.4 to 0.6 wt.-%, calculated as the element and based on 100 wt.-% of the catalyst.

[0112] 10. The catalyst of any one of embodiments 1 to 9, wherein the catalyst comprises promoter metal M1 in an amount ranging from 0.05 to 25 wt.-%, preferably 0.1 to 15 wt.-%, more preferably 0.5 to 10 wt.-%, more preferably 1 to 8 wt.-%, more preferably 2 to 5 wt.-%, and more preferably 3 to 4 wt.-%, calculated as the element and based on 100 wt.-% of the catalyst.

[0113] 11. The catalyst of any one of embodiments 1 to 10, wherein 95 to 100 wt.-%, preferably 97 to 100 wt.-%, more preferably 98 to 100 wt.-%, more preferably 99 to 100 wt.-%, more preferably 99.5 to 100 wt.-%, and more preferably 99.9 to 100 wt.-% of the catalyst consists of Ni, Ru, a promoter metal M1 and one or more support materials, wherein Ni, Ru and the promoter metal M1 may be present as elements, oxides and / or salts, respectively.

[0114] 12. The catalyst of any one of embodiments 1 to 11, wherein the catalyst comprises the one or more promoter metals M1 as hydroxides, bicarbonates and / or carbonates, preferably as hydroxides and / or bicarbonates, and more preferably as hydroxides, wherein more preferably the promoter metal M1 is contained in the catalyst as its hydroxide salt.

[0115] 13. A catalyst as described in any one of Examples 1 to 12, wherein Ru is loaded on the one or more support materials by an impregnation technique using an aqueous solution of one or more ruthenium salts, wherein the one or more ruthenium salts preferably include Ru(NO)(NO3)3, wherein Ru(NO)(NO3)3 is more preferably used as the one or more ruthenium salts.

[0116] 14. The catalyst of any one of embodiments 1 to 13, wherein the catalyst is in the form of a molded article, in the form of an extrudate, and / or in the form of a powder, preferably in the form of a molded article or an extrudate, and more preferably in the form of a molded article.

[0117] 15. The catalyst of embodiment 14, wherein the extrudates have a diameter in the range of 0.5 to 10 mm, preferably 1 to 7 mm, more preferably 1.5 to 5 mm, more preferably 2 to 4 mm, and more preferably 2.5 to 3.5 mm.

[0118] 16. The catalyst according to embodiment 14, wherein the moldings have a diameter in the range of 1 to 20 mm, preferably in the range of 1 to 15 mm.

[0119] 17. The catalyst of embodiment 14 or 16, wherein the molded article is in the shape of a quadrilobate.

[0120] 18. A method for preparing a catalyst comprising Ni, Ru and a promoter metal M1 (preferably a catalyst comprising Ni, Ru and a promoter metal M1 as described in any one of Examples 1 to 17), the method comprising

[0121] (1) preparing a mixture comprising one or more Ni sources, one or more support materials and / or one or more precursors thereof, and water;

[0122] (2) forming the mixture obtained in (1);

[0123] (3) calcining the molded body obtained in (2);

[0124] (4) impregnating the calcined body obtained in (3) with an aqueous solution of one or more Ru salts;

[0125] (5) calcining the impregnated molded body obtained in (4);

[0126] (6) impregnating the calcined shaped body obtained in (5) with an aqueous solution of one or more salts of a promoter metal M1, wherein the promoter metal M1 is selected from the group consisting of Li, K, Na, Cs, Mg, Ca, Sr and Ba, including mixtures of two or more thereof;

[0127] (7) Calcination of the impregnated molded body obtained in (6).

[0128] 19. The method of embodiment 18, wherein in (1), the one or more Ni sources comprise one or more Ni salts, wherein the anions of the one or more Ni salts are preferably selected from the group consisting of halides, carbonates, bicarbonates, sulfates, bisulfates, hydroxides, nitrates, phosphates, hydrogen phosphates, dihydrogen phosphates, acetates, and combinations of two or more thereof,

[0129] More preferably selected from the group consisting of chloride, bromide, fluoride, bicarbonate, bisulfate, nitrate, dihydrogen phosphate, acetate, and combinations of two or more thereof,

[0130] More preferably selected from the group consisting of chloride, fluoride, nitrate, acetate and combinations of two or more thereof,

[0131] Wherein more preferably, the anion of the one or more Ni salts is chloride and / or nitrate, preferably nitrate,

[0132] And wherein more preferably, the one or more Ni sources include nickel (II) nitrate, wherein more preferably, the one or more Ni sources are nickel (II) nitrate.

[0133] 20. The method of embodiment 19, wherein the one or more Ni sources are provided as an aqueous solution of the one or more nickel salts.

[0134] 21. The method of any one of embodiments 18 to 20, wherein in (1), the one or more support materials are selected from the group consisting of metal oxides, wherein the metals of the metal oxides are preferably selected from the group consisting of Al, Si, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, alkaline earth metals and rare earth metals, including combinations of two or more thereof, more preferably selected from the group consisting of Al, Si, Ti, Zr, Mg, Ca, La, Ce, Pr and Nd, including combinations of two or more thereof, more preferably selected from the group consisting of Al, Ti, Zr, Mg, Ca and La, including combinations of two or more thereof, and more preferably selected from the group consisting of Al, Zr and Mg, including combinations of two or more thereof. A combination of two or more, wherein more preferably, the one or more carrier materials comprise one or more metal oxides selected from the group consisting of: Al2O3, ZrO2 and spinel, including mixtures of two or more thereof, preferably selected from the group consisting of: ZrO2 and spinel, including mixtures of two or more thereof, more preferably selected from the group consisting of: ZrO2, NiMgO2 and MgAl2O4, including mixtures of two or more thereof, wherein more preferably, the one or more carrier materials comprise MgAl2O4, preferably NiMgO2 and MgAl2O4, wherein more preferably, the one or more carrier materials consist of MgAl2O4, or NiMgO2 and MgAl2O4, preferably NiMgO2 and MgAl2O4.

[0135] 22. The method of any one of embodiments 18 to 21, wherein in (1), the one or more precursors of the one or more support materials comprise hydrotalcite, wherein preferably, the one or more precursors of the one or more support materials are hydrotalcite.

[0136] 23. A method as described in any one of Examples 18 to 22, wherein (1) includes preparing a mixture comprising one or more Ni sources, one or more precursors of one or more support materials, and water, wherein preferably, (1) consists of preparing a mixture comprising one or more Ni sources, one or more precursors of one or more support materials, and water.

[0137] 24. The method of any one of embodiments 18 to 23, wherein in (2), shaping is achieved by molding or extruding the mixture obtained in (1), preferably by extrusion.

[0138] 25. The method of any one of Embodiments 18 to 24, wherein the calcination in (3) is carried out at a temperature ranging from 500°C to 1,150°C, preferably from 700°C to 1,100°C, more preferably from 850°C to 1,050°C, and more preferably from 950°C to 1,050°C.

[0139] 26. The method of any one of embodiments 18 to 25, wherein the calcination in (3) is carried out for a duration ranging from 0.5 to 9 h, preferably from 1.5 to 6 h, and more preferably from 2 to 3 h.

[0140] 27. The method of any one of embodiments 18 to 26, wherein in (4), the anion of the one or more Ru salts is selected from the group consisting of halide, carbonate, bicarbonate, sulfate, bisulfate, hydroxide, nitrate, phosphate, hydrogen phosphate, dihydrogen phosphate, acetate, and combinations of two or more thereof,

[0141] More preferably selected from the group consisting of chloride, bromide, fluoride, bicarbonate, bisulfate, nitrate, dihydrogen phosphate, acetate, and combinations of two or more thereof,

[0142] More preferably selected from the group consisting of chloride, fluoride, nitrate, acetate and combinations of two or more thereof,

[0143] Wherein more preferably, the anion of the one or more Ru salts is chloride and / or nitrate, preferably nitrate,

[0144] And wherein more preferably, the one or more Ru salts include Ru(NO)(NO3)3, wherein more preferably, the one or more Ru salts are Ru(NO)(NO3)3.

[0145] 28. The method of any one of embodiments 18 to 27, wherein independently of each other, the impregnation in (4) and (6) is accomplished by incipient wetness impregnation.

[0146] 29. The method of any one of embodiments 18 to 28, wherein independently of each other, the calcinations in (5) and (7) are carried out at a temperature in the range of 100°C to 800°C, preferably 350°C to 700°C, more preferably 400°C to 600°C, and more preferably 450°C to 550°C.

[0147] 30. The method of any one of embodiments 18 to 29, wherein independently of each other, the calcinations in (5) and (7) are carried out for a duration ranging from 1 to 9 h, preferably from 1.5 to 6 h, and more preferably from 2 to 3 h.

[0148] 31. A method as described in any of Examples 18 to 30, wherein in (6), the promoter metal M1 is selected from the group consisting of: Li, K, Na, Cs, Mg and Ca, including mixtures of two or more thereof, preferably selected from the group consisting of: Li, K, Na and Cs, including mixtures of two or more thereof, more preferably selected from the group consisting of: Li, K and Na, including mixtures of two or more thereof, wherein more preferably the promoter metal M1 is Li, K, or Li and K, wherein more preferably the promoter metal M1 is K, wherein more preferably the promoter metal M1 consists of Li, K, or Li and K, wherein more preferably the promoter metal M1 consists of K.

[0149] 32. The method of any one of embodiments 18 to 31, wherein in (6), the one or more salts of the promoter metal M1 are selected from the group consisting of hydroxides, bicarbonates and carbonates, including mixtures of two or more thereof, wherein preferably, the one or more salts of the promoter metal M1 are hydroxides and / or bicarbonates, preferably hydroxides, wherein more preferably, in (6), the one or more salts of the promoter metal M1 are hydroxides.

[0150] 33. A catalyst comprising Ni, Ru and a promoter metal M1, preferably the catalyst according to any one of embodiments 1 to 17, obtained or obtainable as according to the method of any one of embodiments 18 to 32.

[0151] 34. A method for reforming ammonia, wherein the method comprises

[0152] (i) providing a reactor containing a catalyst according to any one of embodiments 1 to 17 and 33;

[0153] (ii) preparing a feed gas stream comprising NH3;

[0154] (iii) feeding the feed gas stream prepared in (ii) into the reactor provided in (i), and contacting the feed gas stream with the catalyst;

[0155] (iv) removing an effluent gas stream from the reactor, the effluent gas stream comprising H2 and N2.

[0156] 35. The method of embodiment 34, wherein the contacting in (iii) is carried out at a pressure in the range of 1 to 100 absolute bar, preferably 10 to 75 absolute bar, more preferably 15 to 40 absolute bar, more preferably 18 to 35 absolute bar, more preferably 20 to 28 absolute bar, and more preferably 20 to 25 absolute bar.

[0157] 36. A method as described in embodiment 34 or 35, wherein the contacting in (iii) is carried out at a temperature in the range of 300°C to 1,100°C, preferably 450°C to 1,000°C, preferably 500°C to 900°C, more preferably 500°C to 800°C, more preferably 500°C to 600°C.

[0158] 37. A method as described in any of Examples 34 to 36, wherein the feed gas stream prepared in (ii) contains 1 to 100 vol.-%, preferably 3 to 99.99 vol.-%, more preferably 5 to 99.95 vol.-%, more preferably 10 to 99.9 vol.-%, more preferably 20 to 99.8 vol.-%, more preferably 30 to 99.7 vol.-%, more preferably 40 to 99.6 vol.-%, and more preferably 50 to 99.5 vol.-% NH3.

[0159] 38. A method as described in any of Examples 34 to 37, wherein the feed gas stream prepared in (ii) contains 0 to 50 vol.-%, preferably 0.01 to 30 vol.-%, more preferably 0.03 to 15 vol.-%, more preferably 0.05 to 5 vol.-%, more preferably 0.1 to 1 vol.-%, more preferably 0.12 to 0.5 vol.-%, and more preferably 0.14 to 0.16 vol.-% N2.

[0160] 39. A method as described in any of Examples 34 to 38, wherein the feed gas stream prepared in (ii) contains 0 to 75 vol.-%, preferably 0 to 60 vol.-%, more preferably 0 to 50 vol.-%, more preferably 0 to 40 vol.-%, more preferably 0 to 35 vol.-%, and more preferably 0 to 30 vol.-% H2.

[0161] 40. The method of any one of embodiments 34 to 39, wherein the feed gas stream prepared in (ii) comprises 100 to 50,000 ppmv, preferably 200 to 30,000 ppmv, more preferably 500 to 25,000 ppmv, more preferably 1,000 to 20,000 ppmv, more preferably 3,000 to 15,000 ppmv, more preferably 5,000 to 10,000 ppmv of H2O.

[0162] 41. A method as described in any of Examples 34 to 40, wherein the total amount of NH3, N2 and H2 contained in the feed gas stream prepared in (ii) is in the range of 90 to 100 wt.-%, preferably 95 to 99.95 vol.-%, more preferably 98 to 99.9 vol.-%, more preferably 99 to 99.85 vol.-%, and more preferably 99.7 to 99.8 vol.-%.

[0163] 42. The method of any one of embodiments 34 to 41, wherein the feed stream is heated at 500 to 40,000 h. -1 , preferably 700 to 20,000h -1 , more preferably 800 to 16,000h -1 , more preferably 900 to 10,000h -1 , and more preferably 1,000 to 8,000h -1 The gas hourly space velocity in the range is fed into the reactor.

[0164] 43. A method as described in any one of Examples 34 to 42, wherein, after (i) and before (iii), the catalyst contained in the reactor provided in (i) is reduced in an atmosphere comprising hydrogen and / or NH3, preferably comprising hydrogen.

[0165] 44. A method as described in Example 43, wherein the reduction is carried out at a temperature in the range of 450°C to 1050°C, preferably 500°C to 950°C, more preferably 600°C to 920°C, more preferably 600°C to 890°C, more preferably 600°C to 870°C, and more preferably 600°C to 700°C.

[0166] 45. A method as described in Example 43 or 44, wherein the reduction is carried out in an atmosphere containing 1 to 99 vol.-%, preferably 3 to 90 vol.-%, more preferably 5 to 80 vol.-%, more preferably 6 to 50 vol.-%, more preferably 7 to 30 vol.-%, more preferably 8 to 20 vol.-%, and more preferably 9 to 15 vol.-% H2.

[0167] 46. ​​The method of any one of embodiments 43 to 45, wherein the atmosphere comprises 1 to 99 vol.-%, preferably 5 to 95 vol.-%, more preferably 10 to 90 vol.-%, more preferably 30 to 70 vol.-%, and more preferably 45 to 55 vol.-% of inert gas.

[0168] 47. A method as described in Example 46, wherein the inert gas includes one or more gases selected from the group consisting of: rare gases, CO2 and nitrogen, preferably selected from the group consisting of: He, Ar, Ne, N2 and CO2, wherein more preferably the inert gas includes CO2, N2, or CO2 and N2, wherein more preferably the inert gas includes N2, wherein more preferably the inert gas is N2.

[0169] 48. A method as described in any one of Examples 34 to 47, wherein the method is used to reform ammonia and hydrocarbons, wherein the feed gas stream prepared in (ii) further comprises one or more hydrocarbons and one or more of CO2 and H2O, and wherein the effluent gas stream removed in (iv) further comprises CO.

[0170] 49. A method as described in Example 48, wherein the feed gas stream prepared in (ii) further comprises CO2 and one or more hydrocarbons, and wherein the feed gas stream preferably comprises 5 vol.-% or less H2O, more preferably 3 vol.-% or less, more preferably 1 vol.-% or less, more preferably 0.5 vol.-% or less, more preferably 0.1 vol.-% or less, more preferably 0.05 vol.-% or less, and more preferably 0.01 vol.-% or less H2O.

[0171] 50. A method as described in Example 48, wherein the feed gas stream prepared in (ii) further comprises H2O and one or more hydrocarbons, and wherein the feed gas stream preferably comprises 5 vol.-% or less CO2, more preferably 3 vol.-% or less, more preferably 1 vol.-% or less, more preferably 0.5 vol.-% or less, more preferably 0.1 vol.-% or less, more preferably 0.05 vol.-% or less, and more preferably 0.01 vol.-% or less CO2.

[0172] 51. The method of embodiment 48, wherein the feed gas stream prepared in (ii) further comprises CO2, H2O and one or more hydrocarbons.

[0173] 52. The method of any one of embodiments 48 to 51, wherein the one or more hydrocarbons are selected from the group consisting of alkanes and mixtures thereof, preferably C1-C10 alkanes and mixtures thereof, more preferably C3-C9 alkanes and mixtures thereof, more preferably C4-C8 alkanes and mixtures thereof, more preferably C5-C7 alkanes and mixtures thereof, more preferably C6 alkanes and mixtures thereof.

[0174] 53. The method of any one of embodiments 48 to 52, wherein the contacting is carried out at a pressure in the range of greater than 10 to 50 absolute bar, preferably 12 to 45 absolute bar, more preferably 15 to 40 absolute bar, more preferably 18 to 35 absolute bar, and more preferably 20 to 30 absolute bar.

[0175] 54. A method as described in any of Examples 48 to 53, wherein the feed gas stream prepared in (ii) contains 0.1 to 75 vol.-%, preferably 0.3 to 60 vol.-%, more preferably 0.5 to 50 vol.-%, more preferably 0.8 to 40 vol.-%, and more preferably 1 to 30 vol.-% NH3.

[0176] 55. The method of any one of embodiments 48 to 54, wherein the feed gas stream prepared in (ii) contains 10 to 70 vol.-%, preferably 12 to 60 vol.-%, and more preferably 15 to 50 vol.-% of the one or more hydrocarbons.

[0177] 56. A method as described in any of Examples 48 to 55, wherein the feed gas stream prepared in (ii) contains 0 to 75 vol.-%, preferably 0.5 to 70 vol.-%, more preferably 1 to 68 vol.-%, more preferably 3 to 66 vol.-%, more preferably 5 to 64 vol.-%, more preferably 8 to 62 vol.-%, and more preferably 10 to 60 vol.-% H2O.

[0178] 57. A method as described in any of Examples 48 to 56, wherein the feed gas stream prepared in (ii) contains 0 to 60 vol.-%, preferably 1 to 58 vol.-%, more preferably 3 to 56 vol.-%, more preferably 5 to 54 vol.-%, more preferably 8 to 52 vol.-%, and more preferably 10 to 50 vol.-% CO2.

[0179] 58. The method of any one of embodiments 48 to 57, wherein the feed stream shows a H2O:C molar ratio of H2O to carbon contained in the one or more hydrocarbons in the range of 0 to 4, preferably 0.1 to 3, more preferably 0.3 to 2.5, more preferably 0.4 to 2, and more preferably 0.5 to 1.6.

[0180] 59. A method as described in any of Examples 48 to 58, wherein the feed stream shows a CO2:C molar ratio of CO2 to carbon contained in the one or more hydrocarbons in the range of 0 to 4, preferably 0.1 to 3, more preferably 0.2 to 2, and more preferably 0.3 to 1.5.

[0181] 60. A method as described in any of Examples 48 to 59, wherein the feed stream shows an NH3:C molar ratio of NH3 to carbon contained in the one or more hydrocarbons in the range of 0 to 5, preferably 0 to 4, more preferably 0.001 to 3, more preferably 0.005 to 2, and more preferably 0.01 to 1.

[0182] 61. The method of any one of embodiments 48 to 60, wherein the feed stream is heated at 500 to 16,000 h. -1 , preferably 700 to 14,000h -1 , more preferably 800 to 12,000h -1 , more preferably 900 to 10,000h -1 , and more preferably 1,000 to 8,000h -1 The gas hourly space velocity in the range is fed into the reactor.

[0183] 62. The method of any one of embodiments 48 to 61, wherein the effluent gas stream removed in (iv) further comprises CO2.

[0184] 63. The method of any one of embodiments 48 to 62, wherein the effluent gas stream removed in (iv) shows a stoichiometric number R in the range of 0.1 to 3, wherein R is defined according to formula (I):

[0185]

[0186] wherein c(H2), c(CO2) and c(CO) represent the molar concentrations of H2, CO2 and CO in the effluent gas stream, respectively.

[0187] 64. A method as described in embodiment 63, wherein the stoichiometric number R is in the range of 1 to 2.5, preferably 1.3 to 2.2.

[0188] 65. The method of embodiment 63, wherein R>2.

[0189] 66. The method of any one of embodiments 48 to 62 and 65, wherein the effluent gas stream removed in (iv) shows a H2:CO molar ratio of >2.

[0190] 67. A method as described in embodiment 63, wherein the stoichiometric number R is in the range of 0.5 to 3, preferably 1 to 2.2, and more preferably 1.3 to 1.7.

[0191] 68. A method as described in any of Examples 48 to 67, wherein the effluent gas stream removed in (iv) contains 10 to 90 vol.-%, preferably 20 to 80 vol.-%, more preferably 30 to 70 vol.-%, more preferably 40 to 65 vol.-%, and more preferably 45 to 60 vol.-% H2.

[0192] 69. The method of any one of embodiments 48 to 68, wherein the effluent gas stream removed in (iv) contains 1 to 70 vol.-%, preferably 3 to 50 vol.-%, more preferably 5 to 40 vol.-%, more preferably 10 to 35 vol.-%, and more preferably 15 to 30 vol.-% CO.

[0193] 70. A method as described in any of Examples 48 to 69, wherein the effluent gas stream removed in (iv) contains 1 to 50 vol.-%, preferably 3 to 45 vol.-%, more preferably 5 to 40 vol.-%, more preferably 8 to 35 vol.-%, more preferably 10 to 30 vol.-%, and more preferably 12 to 25 vol.-% CO2.

[0194] 71. The method of any one of embodiments 34 to 70, wherein the effluent gas stream removed in (iv) is used in a process for producing methanol, for producing dimethyl ether, or for producing methanol and dimethyl ether.

[0195] 72. The method of any one of embodiments 34 to 71, wherein the effluent gas stream removed in (iv) is used in a method for producing hydrocarbons, preferably according to a Fischer-Tropsch process.

[0196] 73. The method of any one of embodiments 34 to 72, wherein the effluent gas stream removed in (iv) is used in a method for producing alcohols, preferably alkanols, more preferably C1 to C10 alkanols, more preferably C2 to C8 alkanols, more preferably C2 to C6 alkanols, more preferably C2 to C4 alkanols, more preferably C2 alkanols, and more preferably ethanol.

[0197] 74. A method as described in any one of embodiments 34 to 73, wherein in the initial stage of the method, the feed gas stream prepared in (ii) and fed to the reactor in (iii) further comprises H2 for reducing the catalyst.

[0198] 75. A method as described in Example 74, wherein the feed gas stream prepared in (ii) and fed to the reactor in (iii) further contains 0.5 to 80 vol.-%, preferably 1 to 70 vol.-%, more preferably 2 to 60 vol.-%, more preferably 5 to 50 vol.-%, more preferably 15 to 40 vol.-% H2.

[0199] 76. Use of the catalyst comprising Ni, Ru and a promoter metal M1 as described in any one of embodiments 1 to 17 or 33 in reforming NH3 to N2 and H2. BRIEF DESCRIPTION OF THE DRAWINGS

[0200] Figure 1shows that at 4,000h -1 Results for NH reforming over extruded catalysts at GHSV of 1.3 % and co-feed of 5,000 ppm-vol H O. The extruded catalysts were tested between 300° C. and 650° C. Results obtained for 15 wt.-% Ni supported on MgO / Al O mixed oxide without (catalyst of Reference Example 2) and with (catalyst from Reference Example 3) 0.1 and 0.5 wt.-% Ru promotion are shown, as well as the results obtained for the latter Ru-promoted catalyst additionally promoted with 3.5 wt.-% K according to Example 4 of the invention.

[0201] Figure 2 shows that at 4,000h -1 The results of NH reforming on a pelletized catalyst at a GHSV of 1.5 wt.-%, p(NH)=30 absolute and a co-feed of 5,000 ppm-vol H2O. The pelletized catalyst was tested between 300°C and 650°C. The results obtained for 15 wt.-% Ni supported on a MgO / Al2O3 mixed oxide without (catalyst of Reference Example 2) and with (catalyst from Reference Example 3) 0.5 wt.-% Ru promotion are shown, as well as the results obtained for the latter Ru-promoted catalyst additionally promoted with 3.5 wt.-% K according to Example 4 of the present invention. In addition, for comparison, a catalyst with 15 wt.-% Ni and 3.5 wt.-% KOH but without Ru (catalyst from Comparative Example 5) is included.

[0202] Figure 3 The XRD spectrum of the catalyst of Reference Example 2 is shown, in which the Mg, Al-spinel structure is clearly identified as constituting part of the support material. In the diffraction pattern, a line pattern of MgAl2O4 (without asterisks) and a line pattern of cubic MgNiO2 (with asterisks) are included.

[0203] Experimental Section

[0204] The present invention is further illustrated by the following examples.

[0205] Reference Example 1: Preparation of a Ni (15.5 wt.-%) tabletted catalyst supported on a MgO / Al2O3 mixed oxide

[0206] The catalyst containing Ni is prepared based on the method described in Example E1 of WO 2013 / 068905 A1. In contrast to Example E1 of WO 2013 / 068905 A1, a nickel nitrate aqueous solution (14 wt.-% Ni concentration) is used instead of powdered nickel nitrate hexahydrate. The various ingredients are mixed into a paste, which is extruded. After drying and low-temperature calcination, the extrudate is crushed and sieved to a target fraction with a particle size of 200 to 900 μm.

[0207] The sieved powder was then mixed with 2.8 wt.-% of graphite (Asbury Graphite 3160) and 5.5 wt.-% of cellulose (Arbocel BWW 40). The resulting mixture was tableted into a composition having a composition as described in WO 2020 / 157202 A. Figure 1 The molding of the four-hole cross section is shown. For calcination, the molding is heated in an annealing furnace to a temperature of 1,030° C. to 1,050° C., which is maintained for 4 hours.

[0208] The nickel content of the calcined molding was 15.5% by weight, the magnesium content was 14.0% by weight and the aluminum content was 29.5% by weight.

[0209] Reference Example 2: Preparation of extruded Ni (15.0 wt.-%) catalyst supported on MgO / Al2O3 mixed oxide

[0210] As in Reference Example 1, a catalyst comprising Ni is prepared based on the method described in Example E1 of WO 2013 / 068905 A1. The Ni salt solution used in Reference Example 1 is mixed with hydrotalcite and an appropriate amount of water to prepare an extrudable paste. The paste is extruded in the next step. The subsequent heat treatment of the obtained extrudate is maintained between 850°C and 1050°C.

[0211] The nickel content of the calcined extrudates was 15.0 wt.-%, the magnesium content was 14.0 wt.-% and the aluminum content was 29.5 wt.-%.

[0212] Reference Example 3: Promotion of the Ni catalysts of Examples 1 and 2 with Ru (0.1 and 0.5 wt.-%)

[0213] The catalysts prepared in Examples 1 and 2 were impregnated with Ru(NO(NO3)3) solution, respectively, based on the water absorption of the materials. The Ru loading was fixed at 0.1 and 0.5 wt-%. In addition, the impregnated samples were heat treated up to 500°C, respectively.

[0214] Example 4: Promotion of the Ni / Ru catalyst of Example 3 with K (3.5 wt.-%)

[0215] The catalysts prepared in Example 3 were impregnated separately with KOH solution based on the water absorption of the material. The KOH loading was fixed at 3.5 wt.-% of K (5 wt.-% of KOH). In addition, the impregnated samples were heat treated up to 500°C.

[0216] Comparative Example 5: Promoting the Ni catalyst of Example 1 with K (3.5 wt.-%)

[0217] The catalyst prepared in Example 1 was impregnated with KOH solution based on the water absorption of the material. The KOH loading was fixed at 3.5 wt.% of K (5 wt.-% of KOH) and the impregnated sample was heated to 500°C.

[0218] Example 6: Catalytic testing in NH3 reforming at high pressure

[0219] The catalysts of Examples 1 to 5 were activated at a temperature of 450° C. to 850° C. in an inert gas (Ar or N 2 ) in a reducing atmosphere of 5-50 vol.-% H 2 . The catalytic NH 3 reforming tests were carried out at an ammonia partial pressure (p(NH 3 )) of 20 bar (see results in Table 1 ) and 30 bar (see results in Table 2 ). A fraction of 5,000 vol.-ppm of H 2 O was added to the NH 3 feed. In addition, the catalysts were heated to 4,000 h. -1 The test was conducted under GHSV of 1.3 GHz and the temperature varied from 300°C to 650°C. The variation of NH3 conversion with temperature is shown in Figure 1 and Figure 2 and in Tables 1 and 2.

[0220] Table 1. Results of ammonia conversion over Ni-based catalysts (extrudates) of Reference Examples 2 and 3 and Example 4.

[0221]

[0222] Therefore, as can be seen from Table 1 and Figure 1From the results obtained from the tests of the corresponding catalysts shown in , it can be concluded that the promotion of the Ni-based catalyst of reference example 2 with a relatively small amount of Ru already leads to a significant improvement in the ammonia conversion, wherein for the catalyst of reference example 3, a higher conversion can already be obtained at a lower temperature. However, quite unexpectedly, the further addition of K as a promoter in the Ru-promoted Ni catalyst in example 4 leads to a significant increase in the ammonia conversion at a lower temperature, so that an ammonia conversion of 50% is already achieved at 490° C. In addition, the catalyst according to the invention of example 4 shows an ammonia conversion corresponding to the equilibrium conversion at about 600° C., while the Ni catalyst of reference example 2 shows only a conversion of slightly more than 60% at this temperature, and the conversion of the Ru-promoted Ni catalyst of reference example 3 does not exceed 77%. Therefore, it has been found quite unexpectedly that the use of a relatively low amount of Ru in a Ni-based catalyst promoted with K provides unexpectedly high conversions at low temperatures when used for the decomposition of ammonia, wherein only a small amount of Ru is required to obtain an efficient catalyst.

[0223] Table 2. Results of ammonia conversion over Ni-based catalysts (tablets) of Reference Examples 1 and 3 and Examples 4 and 5.

[0224]

[0225] On the other hand, from Table 2 and Figure 2 The results obtained from the tests of the corresponding catalysts shown in Table 1 and Figure 1 The results obtained with the pelletized Ni catalyst of Reference Example 1 are comparable to those obtained with the extruded Ni catalyst of Reference Example 2 shown in Table 2. Therefore, the same applies to the pelletized catalyst of Reference Example 3 loaded with 0.5 wt.-% Ru and the pelletized catalyst of Example 4 loaded with 0.5 wt.-% Ru and 3.5 wt.% K according to the present invention. Figure 2 In the Figures 2 and 3, the results obtained using a tableted Ni catalyst loaded with only 3.5 wt.-% of K according to Comparative Example 5 are shown for comparison. From these results, it can be seen that the Ni catalyst of the comparative example, which contains only K and does not additionally contain any Ru, shows significantly worse performance than the Ni catalyst of Reference Example 1. It has thus been found, quite unexpectedly, that a very strong synergistic effect can be achieved by adding small amounts of Ru to a catalyst containing Ni and K, wherein the effect is greater than the degree of improvement observed when the same small amount of Ru is added to a catalyst containing only Ni.

[0226] Thus, it has been found very unexpectedly that the catalyst of the present invention shows a very strong synergistic effect between the Ni, Ru, and K components, which was by no means expected, when considering the results obtained for a catalyst containing only Ni, a catalyst containing only Ni and Ru, and a catalyst containing only Ni and K. This result is even more surprising in view of the fact that the performance of the catalyst containing only Ni and K is significantly worse than that of the catalyst containing only Ni.

[0227] Prior Art Cited:

[0228] -I.Lucentini et al.,Ind.Eng.Chem.Res.2021,60,18560-18611

[0229] -T.Le et al.,Korean J.Chem.Eng.,2021,38(6),1087-1103

[0230] -Bell et al.,Top Catal.,2016,59,1438–1457

[0231] -X.-K.Li et al.,Journal of Catalysis,2005,236,181–189.

Claims

1. A catalyst comprising Ni, Ru and a promoter metal M1, wherein the catalyst shows a Ru:Ni weight ratio in the range of 0.0001:1 to 0.5:1, wherein the promoter metal M1 is selected from the group consisting of: Li, K, Na, Cs, Mg, Ca, Sr and Ba, including mixtures of two or more thereof, and wherein the catalyst further comprises one or more support materials on which Ni, Ru and the promoter metal M1 are respectively loaded.

2. The catalyst according to claim 1, wherein The catalysts showed Ni:M1 atomic ratios ranging from 0.1:1 to 30:

1.

3. The catalyst as claimed in claim 1 or 2, comprising Ni in an amount in the range of 1 to 75 wt.-%, calculated as element and based on 100 wt.-% of the catalyst.

4. The catalyst as claimed in any one of claims 1 to 3, comprising Ru in an amount in the range of 0.01 to 5 wt.-%, calculated as the element and based on 100 wt.-% of the catalyst.

5. The catalyst as claimed in any one of claims 1 to 4, comprising the promoter metal M1 in an amount in the range of 0.05 to 25 wt.-%, calculated as the element and based on 100 wt.-% of the catalyst.

6. The catalyst according to any one of claims 1 to 5, wherein The catalyst comprises the one or more promoter metals M1 as hydroxides, bicarbonates, and / or carbonates.

7. The catalyst according to any one of claims 1 to 6, wherein The catalyst is in the form of a molding, in the form of an extrudate, and / or in the form of a powder.

8. A method for preparing a catalyst according to any one of claims 1 to 7, the method comprising (1) preparing a mixture comprising one or more Ni sources, one or more support materials and / or one or more precursors thereof, and water; (2) shaping the mixture obtained in (1); (3) calcining the molded body obtained in (2); (4) impregnating the calcined body obtained in (3) with an aqueous solution of one or more Ru salts; (5) calcining the impregnated molded body obtained in (4); (6) impregnating the calcined shaped body obtained in (5) with an aqueous solution of one or more salts of a promoter metal M1, wherein the promoter metal M1 is selected from the group consisting of Li, K, Na, Cs, Mg, Ca, Sr and Ba, including mixtures of two or more thereof; (7) Calcination of the impregnated molded body obtained in (6).

9. A method for reforming ammonia, wherein: The method includes (i) providing a reactor containing a catalyst according to any one of claims 1 to 7; (ii) preparing a feed gas stream comprising NH3; (iii) feeding the feed gas stream prepared in (ii) into the reactor provided in (i), and contacting the feed gas stream with the catalyst; (iv) removing an effluent gas stream from the reactor, the effluent gas stream comprising H2 and N2.

10. The method of claim 9, wherein: The contacting in (iii) is performed at a temperature ranging from 300°C to 1,100°C.

11. The method according to claim 9 or 10, wherein: The feed gas stream prepared in (ii) comprises 100 to 50,000 ppmv H2O.

12. The method according to any one of claims 9 to 11, wherein: The total amount of NH3, N2 and H2 contained in the feed gas stream prepared in (ii) is in the range of 90 to 100 wt.-%.

13. The method according to any one of claims 9 to 12, wherein: The feed stream is adjusted to 500 to 40,000 h -1 The gas hourly space velocity in the range is fed into the reactor.

14. The method according to any one of claims 9 to 13, wherein: After (i) and before (iii), the catalyst contained in the reactor provided in (i) is reduced in an atmosphere comprising hydrogen and / or NH 3 .

15. Use of the catalyst according to any one of claims 1 to 7 in the reforming of NH3 to N2 and H2.

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