A nickel-based supported multi-metallic catalyst, a preparation method thereof and application thereof in reforming reaction

Abstract

This application relates to the field of catalytic materials and energy conversion technology, and provides a nickel-based supported multimetallic catalyst, its preparation method, and its application in reforming reactions. The catalyst includes an oxide support and a multimetallic active component supported on the surface and / or within the pores of the oxide support; wherein the oxide support includes at least one of alumina, silica, zirconium oxide, magnesium oxide, and composite oxides; the multimetallic active component includes Ni, and at least one of Co, La, Mn, and Ca. The catalyst of this application can be used in the reforming of tar, pyrolysis gas, and biomass-derived oxygen-containing organic matter to syngas; thereby solving the technical problem that existing Ni-based catalysts are prone to carbon deposition and deactivation during reforming reactions, leading to insufficient catalytic stability, and improving the reaction stability of the catalyst.

Description

Technical Field

[0001] This invention relates to the field of catalytic materials and energy conversion technology, and more specifically, to a nickel-based supported multimetallic catalyst, its preparation method, and its application in reforming reactions. Background Technology

[0002] Reforming to produce syngas is a crucial technological pathway for the high-value conversion of tar, pyrolysis gas, and biomass-derived oxygen-containing organic matter, showing promising applications in biomass energy utilization, waste organic resource conversion, and clean fuel production. In related reforming reactions, the composition and structure of the catalyst significantly influence reaction activity, stability, and resistance to deactivation. In recent years, multi-metal catalytic materials containing various metal components have demonstrated good thermal stability, structural stability, and anti-sintering ability in high-temperature reaction environments due to the synergistic effect of multiple components. Therefore, they show promising application prospects in methane reforming, carbon dioxide reforming, steam reforming, tar reforming, biomass conversion, and other hydrocarbon reforming reactions.

[0003] Existing methods for preparing multi-metal catalysts mainly include sol-gel methods, co-precipitation methods, and impregnation methods. However, these methods typically suffer from problems such as long process flows, demanding equipment requirements, high costs, difficulties in scale-up, or uneven dispersion of multiple components. Especially for supported multi-metal catalysts, it is often difficult to simultaneously achieve uniform distribution of multiple components, particle size control, and industrial scale-up feasibility, thus affecting their application in actual reforming reactions.

[0004] In complex feedstock systems such as tar reforming and pyrolysis gas reforming, catalysts not only need high activity but also good resistance to coking and long-term stable operation. Existing Ni-based catalysts are widely used in reforming reaction systems due to their relatively low cost and high activity in breaking carbon-hydrogen bonds. However, existing Ni-based catalysts still suffer from significant coking and deactivation problems in actual reforming processes. Especially under complex carbon source conditions such as tar, pyrolysis gas, and biomass-derived oxygen-containing organic matter, aromatic hydrocarbons, polycyclic aromatic hydrocarbons, and easily condensed intermediates in the feedstock are prone to cracking, condensation, and deposition on the catalyst surface, leading to coking. Coking not only obscures active sites on the catalyst surface, reducing catalytic activity, but can also clog support pores, affecting the mass transfer process between reactants and products, thus causing a decrease in catalyst stability and, in severe cases, even rapid catalyst deactivation. Therefore, to address the technical problem of easy coking and deactivation of existing Ni-based catalysts during reforming reactions, resulting in insufficient catalytic stability, there is an urgent need to develop a nickel-based supported multimetal catalyst to solve these problems. Summary of the Invention

[0005] This invention aims to provide a nickel-based supported multimetallic catalyst, its preparation method, and its application in reforming reactions. The catalyst of this application can be used in the reforming reaction of tar, pyrolysis gas, and biomass-derived oxygen-containing organic matter to produce syngas, thereby solving the technical problem that existing Ni-based catalysts are prone to carbon deposition and deactivation during the reforming process, resulting in insufficient catalytic stability, and improving the reaction stability of the catalyst.

[0006] To address the aforementioned problems, this invention provides a nickel-based supported multimetal catalyst, comprising an oxide support and a multimetal active component supported on the surface and / or within the pores of the oxide support; wherein the oxide support comprises at least one of alumina, silicon oxide, zirconium oxide, magnesium oxide, and composite oxides; and the multimetal active component comprises Ni, and at least one of Co, La, Mn, and Ca.

[0007] In the above technical solution, the carrier includes Al2O3.

[0008] In the above technical solution, the multi-metal active components include Ni, Co, La, Mn, and Ca.

[0009] In the above technical solution, the total loading of the multi-metal active components is 5~20wt% based on the total mass of the catalyst.

[0010] In the above technical solution, based on the total mass of the catalyst, the content of Ni is 2~15wt%, the content of Co is 1~5wt%, the content of La is 0.2~2wt%, the content of Mn is 0.2~2wt%, and the content of Ca is 0.2~2wt%.

[0011] This invention provides a method for preparing a nickel-based supported multimetal catalyst. The method is used to prepare any of the above-mentioned nickel-based supported multimetal catalysts and includes the following steps: S100. The oxide carrier and the multi-metal precursor are added into a ball milling device and mixed by ball milling under the action of grinding media to obtain precursor powder. S200: The precursor powder is dried and calcined to obtain a supported multi-metal precursor catalytic material. S300, the supported multi-metal precursor catalyst material is reduced to obtain a nickel-based supported multi-metal catalyst; The multimetallic precursors include Ni precursors, and at least one of Co precursors, La precursors, Mn precursors and Ca precursors.

[0012] In the above technical solution, in S100, the ball milling speed is 100~600 rpm and the time is 3~9h; the grinding media is a combination of one or more grinding balls with different particle sizes; the ball milling mode adopts an alternating combination of forward rotation, stop rotation and reverse rotation.

[0013] In the above technical solution, in S200, the drying temperature is 80~120℃ and the time is 6~12h; the calcination temperature is 500~800℃ and the time is 4~6h.

[0014] In the above technical solution, in S300, the reduction treatment temperature is 400~800℃ and the time is 2~4h.

[0015] The present invention also provides a method for producing syngas through reforming, wherein a carbon-containing feedstock is fed into a reactor and reformed under the action of any of the above-mentioned nickel-based supported multimetallic catalysts to obtain syngas; wherein the carbon-containing feedstock includes at least one of tar, pyrolysis gas, and biomass-derived oxygen-containing organic matter.

[0016] Beneficial effects 1. This invention constructs a multi-metal synergistic active system by introducing at least one of Co, La, Mn and Ca into a Ni-based catalytic system, which can improve the catalyst's resistance to carbon deposition and reaction stability while ensuring reforming activity; 2. The preparation route of ball milling, drying, calcination and reduction adopted in this invention is beneficial to improve the contact uniformity and composite degree between the multi-metal components and the oxide support, thereby improving the dispersion of active components and improving the overall performance of the catalyst. 3. The nickel-based supported multimetal catalyst provided by this invention is suitable for the reforming of complex carbonaceous raw materials such as tar, pyrolysis gas and biomass-derived oxygen-containing organic matter to produce syngas, and can improve tar removal rate, syngas yield and gas quality. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort: Figure 1 The graph shows a comparison of syngas yield and H2 / CO ratio in Examples 1-8 and Comparative Examples 1-2 during biomass tar gas reforming. Figure 2 The tar removal rate and tar yield in biomass tar gas reforming of Examples 1-8 and Comparative Examples 1-2 are shown. Detailed Implementation

[0018] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, a detailed description of specific embodiments of the present invention will be provided below.

[0019] Unless otherwise specified, all reagents and raw materials used in this invention are commercially available. Experimental methods in the following examples that do not specify particular conditions should be performed according to conventional methods and conditions, or as selected in the product instructions.

[0020] This invention provides a nickel-based supported multimetallic catalyst, its preparation method, and its application in reforming reactions, addressing the technical problem of insufficient catalytic stability caused by carbon deposition and deactivation during reforming processes. The catalyst of this invention comprises an oxide support and a multimetallic active component supported on the surface and / or within the pores of the oxide support; wherein the oxide support includes at least one of alumina, silica, zirconium oxide, magnesium oxide, and composite oxides; the multimetallic active component includes Ni, and at least one of Co, La, Mn, and Ca.

[0021] The catalyst of this invention primarily serves to provide highly efficient active sites, promote the conversion of feedstock molecules, increase syngas yield, and enhance catalyst stability in reforming reactions. Specifically, Ni, as the main active metal, can effectively activate the CH bonds, CC bonds, and some CO bonds of feedstock molecules such as methane, light hydrocarbons, tar, and biomass-derived oxygen-containing organic compounds, thereby promoting the reforming reaction towards the generation of H2 and CO. This is the core basis for the catalyst to obtain high reactivity. Simultaneously, the introduction of Co can form synergistic active centers with Ni, improving the electronic environment and geometry around Ni, enhancing the stability of the active metal at high temperatures, and to some extent inhibiting Ni particle migration and aggregation, thus helping to maintain a high exposure of active sites. Therefore, this invention does not simply rely on increasing the Ni content to obtain activity, but rather improves the utilization efficiency and reaction stability of Ni through a multi-metal synergistic approach.

[0022] Preferably, the present invention uses a high specific surface area material as the oxide support, including at least one of alumina, silicon oxide, zirconium oxide, magnesium oxide, and composite oxides. The high specific surface area oxide support provides a larger loading area, abundant anchoring sites, and a suitable pore structure, allowing the multi-metal components to be more uniformly distributed on the support surface and within the pores, thereby reducing local enrichment and particle growth, and improving the mass transfer process between reactants and products. The introduction of La enhances the metal-support interaction and improves the surface properties and thermal stability of the support, further improving the anchoring ability of the active components under high-temperature conditions. Mn helps improve the oxygen migration capacity and redox properties of the catalyst surface, making it easier for surface carbon intermediates to continue to transform or be removed. Ca is mainly used to regulate the alkalinity of the catalyst surface, inhibiting acidic site-induced deep cracking, polymerization, and coking side reactions, and promoting the removal of carbon deposition precursors. Therefore, La, Mn, and Ca do not individually assume the main activity, but rather regulate the interfacial environment, surface acidity / alkalinity, and surface reaction pathways around the Ni main active center, thereby significantly improving the overall performance of the catalyst.

[0023] It is understood that the multi-metallic active components of this invention are not simply piled on the outer surface of the support, but are more uniformly distributed on the surface and / or within the pores of the oxide support under the action of ball milling and subsequent heat treatment, forming a composite active region with Ni as the core, Co as a synergist, and La, Mn, and Ca as the interface regulators. Ni mainly undertakes the main activity of the reforming reaction, Co mainly enhances the synergistic activation and structural stability, and La, Mn, and Ca mainly improve the interface structure, regulate the surface properties, and inhibit carbon deposition. This enables the catalyst of this invention to simultaneously maintain high activity, strong anti-sintering ability, excellent anti-carbon deposition ability, and good long-term operational stability in complex systems such as methane reforming, tar reforming, pyrolysis gas reforming, and biomass-derived oxygen-containing organic matter reforming.

[0024] In addition, the total loading of the multi-metal active components is 5~20wt% based on the total mass of the catalyst, which can ensure that the catalyst has a sufficient number of active sites, while avoiding excessive metal loading that could lead to particle accumulation, pore blockage and intensified sintering.

[0025] Furthermore, based on the total mass of the catalyst, the content of Ni is 2-15 wt%, the content of Co is 1-5 wt%, the content of La is 0.2-2 wt%, the content of Mn is 0.2-2 wt%, and the content of Ca is 0.2-2 wt%. The Ni content of 2-15 wt% can balance the main reaction activity and dispersion stability; the Co content of 1-5 wt% is conducive to exerting the synergistic effect with Ni without excessively weakening the dominant position of Ni; the La, Mn, and Ca are each controlled at 0.2-2 wt%, which can effectively exert the functions of interface regulation, anti-sintering and anti-carbon deposition without excessively covering the active sites.

[0026] In specific implementation, this invention provides a method for preparing a nickel-based supported multimetal catalyst. The method, used to prepare any of the aforementioned nickel-based supported multimetal catalysts, includes the following steps: S100. The oxide carrier and the multi-metal precursor are added into a ball milling device and mixed by ball milling under the action of grinding media to obtain precursor powder. S200: The precursor powder is dried and calcined to obtain a supported multi-metal precursor catalytic material. S300, the supported multi-metal precursor catalyst material is reduced to obtain a nickel-based supported multi-metal catalyst; The multimetallic precursors include Ni precursors, and at least one of Co precursors, La precursors, Mn precursors and Ca precursors.

[0027] In S100, the oxide support and multi-metal precursor are added to a ball mill and mixed under the action of grinding media to obtain precursor powder. Mechanical force enables efficient, uniform, and sufficient contact and composite between different metal precursors and support particles, thus avoiding problems such as excessively high local concentrations, uneven metal distribution, and local enrichment on the support surface that are prone to occur in traditional impregnation or simple stirring processes. For this invention, since the active component is not a single Ni, but includes Ni and at least one of Co, La, Mn, and Ca, the spatial distribution of multiple components directly affects the formation path of the active phase during subsequent calcination and reduction processes. If the initial mixing is insufficient, problems such as certain metals forming separate phases, local sintering, or difficulty in forming stable composite active centers may easily occur later. Therefore, S100 lays the foundation for multi-metal synergy before catalyst formation.

[0028] Furthermore, ball milling allows for closer contact between the carrier and the metal precursor. Ball milling also refines particles, increases the solid-solid interface area, and even induces surface defects and high-energy sites locally, thereby improving the uniformity of precursor decomposition, metal species migration, and composite phase formation during subsequent heat treatment. The ball milling speed should be controlled between 100 and 600 rpm. Too low a speed results in insufficient impact and shearing, making it difficult for the multi-metal precursor and carrier to fully and uniformly combine; too high a speed can easily cause localized overheating, excessive particle breakage, or even premature decomposition or agglomeration of some precursors due to excessive mechanical action. The milling time should be between 3 and 9 hours. Too short a time results in insufficient mixing and activation; too long a time may lead to excessively fine particles, increased agglomeration, or equipment wear and contamination. Using grinding balls of different sizes—larger balls provide stronger impact to break up agglomerates, while smaller balls help fill gaps and enhance refinement and homogenization—combined efforts can improve ball milling efficiency. Using an alternating combination of forward rotation, stop rotation, and reverse rotation helps to avoid localized deposition and dead zone accumulation caused by unidirectional continuous ball milling, allowing the material to continuously change its direction of movement and stress state, thereby further improving the mixing uniformity and reducing agglomeration.

[0029] Preferably, the multi-metal precursor includes at least one or more of nitrates, acetates, chlorides, acetylacetones, oxalates, citrates, ammonium salts, and organometallic salts; the precursor can decompose during subsequent drying and calcination to form corresponding metal oxides, composite oxides, and / or precursor active phases.

[0030] Those skilled in the art will know that the proportions of the various metal components are controlled by molar ratio, mass ratio, or atomic ratio according to the requirements of the target reforming reaction for activity, anti-coking performance, and stability.

[0031] In S200, the precursor powder undergoes drying and calcination to obtain a supported multi-metal precursor catalytic material. First, the drying process removes adsorbed water, crystal water, or trace amounts of volatile components that may be present in the ball-milled system, stabilizing the precursor state and preventing these volatile components from rapidly escaping during subsequent calcination, which could cause local structural disturbances, pore collapse, or uncontrolled metal species migration. Second, the calcination process induces thermal decomposition and solid-phase transformation of various metal precursors, forming metal oxides, composite oxides, or highly dispersed precursor active phases supported on the surface and / or within the pores of the support. Simultaneously, it promotes a more stable interfacial bond between the precursor and the support, laying the foundation for subsequent reduction to generate truly active metal sites.

[0032] Furthermore, the drying stage transitions the system from a relatively unstable precursor mixture state to a heat-treated stable state, reducing the sudden changes during subsequent calcination. The calcination stage, through heat input, causes precursors such as nitrates, acetates, and acetylacetones to gradually lose their organic ligands or anionic components, transforming them into corresponding metal oxides or composite oxides, and redistributing and fixing these metal species on the support surface. Simultaneously, elements such as La, Mn, and Ca also participate in interface reconstruction during this process, improving metal-support interactions and inhibiting excessively rapid growth of metal particles during subsequent reduction.

[0033] Preferably, the drying temperature is 80~120℃ and the time is 6~12h, which can remove moisture and low-boiling volatiles relatively gently, while avoiding premature decomposition or local agglomeration of some precursors due to excessively high temperature. If the drying temperature is too low or the time is too short, there will be more residual volatiles, which is not conducive to uniform calcination in the subsequent process. If the temperature is too high or the time is too long, it may cause local instability of the precursor, which is not conducive to the formation of a uniform precursor structure. The calcination temperature is 500~800℃ and the time is 4~6h because the precursor decomposes incompletely at lower temperatures, making it difficult to form a stable metal oxide precursor phase, and the metal-carrier interface is insufficient. Appropriately increasing the temperature is conducive to the full decomposition of the precursor, enhanced interfacial bonding, and the formation of a multi-metal oxide precursor structure. However, if the temperature is too high or the time is too long, it is easy to cause metal oxide grain growth, decrease in specific surface area, and loss of some pore structure.

[0034] In S300, the supported multi-metal precursor catalyst is reduced to obtain a nickel-based supported multi-metal catalyst. After S200, most of the metal components in the system still exist in oxidized or complex oxidized states. The truly suitable high-activity sites for reforming reactions usually originate from metallic Ni and the alloyed, near-alloyed, solid-solution, or high-entropy approximation structures formed between Ni and other metals. Therefore, S300 transforms the metal oxide precursor phase into the actual active metal phase, while simultaneously promoting the formation of closer composite active centers between Ni and reduceable metals such as Co. It also allows components such as La, Mn, and Ca to play structural and interfacial regulatory roles around the metal phase or at the metal-support interface.

[0035] Furthermore, the reduction process not only transforms oxides such as NiO into metallic Ni, but also, under a high-temperature reducing atmosphere, various metal species undergo rearrangement, migration, and interfacial reconstruction, causing Ni to form alloy phases, solid solution phases, or high-entropy near-active structures with components such as Co. This multi-metal composite active phase typically possesses superior electronic structure, geometry, and thermal stability compared to single Ni metal particles. Specifically, it can improve the adsorption-activation behavior of reactants, enhance CH bond breaking and reforming conversion efficiency; simultaneously, the coexistence of multiple components and the resulting lattice distortion, interfacial synergy, and thermodynamic stabilization effects also help suppress the migration and sintering of active particles at high temperatures. In addition, after two-step heat treatment (S200 and S300), components such as La, Mn, and Ca are more easily distributed on the periphery of the metal phase or at the interface, thereby regulating surface alkalinity, improving oxygen migration capacity, and inhibiting carbon deposition.

[0036] Specifically, Ni and Co form alloy phases, solid solution phases, or locally highly mixed composite active phases during the reduction process. La, Mn, and Ca are distributed around the active phase and / or at the metal-support interface to play a role in interface regulation, surface alkalinity adjustment, oxygen migration promotion, and anti-coking, thereby giving the active center multi-principal synergistic characteristics. This high-entropy alloy structure or high-entropy approximation structure can improve the dispersion stability of active components, inhibit high-temperature sintering and particle growth, and improve surface reaction pathways and coking intermediate transformation behavior through multi-component synergistic effects, lattice distortion effects, and thermal stabilization effects. This endows the catalyst with higher reforming activity, stronger anti-coking ability, and better long-term operational stability.

[0037] Preferably, the reduction temperature is controlled at 500~800℃ and the time is controlled at 2~4h. If the reduction temperature is too low or the time is too short, metal oxides such as Ni and Co cannot be fully reduced, the active metal sites are insufficient, and the catalytic activity is difficult to fully exert. If the reduction temperature is too high or the time is too long, although the reduction is more thorough, it is also easier to cause metal particles to grow and the surface exposed structure to become unbalanced, thereby weakening the dispersibility and increasing the risk of subsequent sintering.

[0038] This invention also provides a method for producing syngas through reforming. A carbon-containing feedstock is fed into a reactor, and a reforming reaction is carried out under the action of any of the aforementioned nickel-based supported multimetallic catalysts to obtain syngas. The nickel-based supported multimetallic catalyst catalyzes the transformation of complex carbon-containing feedstocks, causing the macromolecular organics, light hydrocarbons, and oxygen-containing intermediates in the feedstocks to undergo cracking, reforming, dehydrogenation, bond breaking, and rearrangement reactions, thereby converting them into syngas products mainly composed of H2 and CO. Compared with direct thermal cracking or non-catalytic thermal conversion, this invention, by introducing a nickel-based supported multimetallic catalyst, can significantly improve the conversion efficiency of carbon-containing feedstocks, tar removal capacity, and syngas yield, while reducing the residue of by-product coke and difficult-to-convert intermediates, thereby improving the stability of the entire reforming process and the quality of the gaseous products.

[0039] Specifically, carbon-containing raw materials include at least one of tar, pyrolysis gas, and biomass-derived oxygen-containing organic matter. These raw materials typically have complex compositions, diverse molecular structures, and generally suffer from problems such as easy condensation, easy coking, poor thermal stability, and multiple conversion pathways. Tar often contains aromatic, fused-ring, and high-boiling-point organic compounds, which are difficult to completely decompose by thermal action alone and are prone to further condensation at high temperatures to form carbon deposits. In addition to combustible small molecules, pyrolysis gas usually contains some tar vapor and unstable intermediates, which can easily cause blockage and deactivation during subsequent utilization. Biomass-derived oxygen-containing organic matter contains more alcohols, ketones, aldehydes, acids, phenols, and ethers. Its reaction process involves multiple pathways, including CH bond activation, C / C bond breaking, CO bond breaking, decarbonylation, decarboxylation, and reforming. Therefore, the present invention selects the above-mentioned catalyst for the reforming of these complex carbon-containing raw materials, essentially to give full play to the comprehensive advantages of Ni main active center, multi-metal synergistic active center and interface regulation component, so that different types of molecules in complex raw materials can enter the controllable conversion pathway more effectively, thereby improving the syngas generation efficiency and inhibiting carbon deposition and deactivation.

[0040] Preferably, the reforming reaction temperature is 500~800℃. Reforming reactions involve tar reforming, pyrolysis gas reforming, and oxygen-containing organic matter reforming. Essentially, these are high-temperature endothermic reactions or bond-breaking transformation processes requiring high activation energy. Only at higher temperatures are the CH bonds, CC bonds, and some CO bonds of the raw material molecules more easily activated, and tar macromolecules and difficult-to-crack components are more likely to undergo initial cracking and subsequent reforming. Secondly, this range balances reaction activity and catalyst stability: when the temperature is too low, the cracking of complex organic matter is insufficient, the tar removal rate is low, and intermediate carbon deposit precursors are easily generated, which accelerates coking on the catalyst surface; while when the temperature is too high, although it is beneficial to improve the conversion rate, it will also exacerbate metal particle migration and sintering, accelerate changes in the support structure, and increase equipment energy consumption and heat load.

[0041] Furthermore, before the reforming reaction, the catalyst is first loaded into the reactor and pre-activated under a reducing atmosphere before the carbon-containing feedstock is introduced for the reforming reaction. The reason for loading and pre-activating the catalyst is that at least some of the Ni and Co in the prepared catalyst may still exist in oxidized, composite oxidized, or precursor active phases before entering the reactor. The catalyst that truly plays a major catalytic role in the reforming reaction is usually metallic Ni and the Ni-Co composite active phase. Pre-activation before the reaction converts NiO and other oxides into metallic Ni and promotes the further formation of alloy phases, solid solution phases, or high-entropy near-composite active structures between Ni and Co, thus ensuring the catalyst is in a highly active state before the formal feed. This avoids insufficient conversion, intermediate accumulation, or initial carbon buildup due to insufficient catalyst activation when the feedstock first enters; and it facilitates the construction of active centers under a milder, more controllable atmosphere, avoiding the instability caused by simultaneous activation and reaction in complex carbon-containing feedstocks. Example 1

[0042] This embodiment provides a nickel-based supported multimetal catalyst and its preparation method. The total loading of the multimetal active components is 15 wt% by total catalyst mass, wherein the content of Ni is 10.0 wt%, the content of Co is 2.5 wt%, the content of La is 0.75 wt%, the content of Mn is 0.875 wt%, and the content of Ca is 0.875 wt%. The support is γ-Al₂O₃. The preparation method includes the following steps: S100. Add 85.5g of γ-Al2O3 to a ball mill jar, then add 49.6g of nickel nitrate hexahydrate, 12.4g of cobalt nitrate hexahydrate, 2.4g of lanthanum nitrate hexahydrate, 4.0g of manganese nitrate tetrahydrate, and 5.1g of calcium nitrate tetrahydrate. Add grinding balls of different particle sizes as grinding media to the ball mill jar, including zirconia balls with diameters of 5mm, 10mm, and 15mm. Set the ball milling program to an alternating cycle of 30min forward rotation, 10min stop, 30min reverse rotation, and 10min stop, and ball mill at 400rpm for 6h to obtain the precursor powder. S200. The precursor powder is placed in a forced-air drying oven and dried at 100°C for 12 hours. Then the dried powder is placed in a muffle furnace and calcined at 800°C in air for 6 hours to obtain a supported multi-metal precursor catalyst material. S300. The supported multi-metal precursor catalyst is placed in a tube furnace and reduced at 650°C for 3 hours under H2 atmosphere to obtain a nickel-based supported multi-metal catalyst. Example 2

[0043] This embodiment provides a nickel-based supported multimetal catalyst and its preparation method. The formulation and preparation method are as shown in Example 1, except that the ball milling time in S100 is 3 hours. Example 3

[0044] This embodiment provides a nickel-based supported multimetal catalyst and its preparation method. The formulation and preparation method are as shown in Example 1, except that the ball milling time in S100 is 9 hours. Example 4

[0045] This embodiment provides a nickel-based supported multimetal catalyst and its preparation method. The total loading of the multimetal active components is 10.0 wt% by total catalyst mass, wherein the content of Ni is 8.0 wt%, the content of Co is 1.0 wt%, the content of La is 0.2 wt%, the content of Mn is 0.4 wt%, and the content of Ca is 0.4 wt%. The preparation method is basically the same as in Example 1, except that: In S100, 90.0g of γ-Al2O3 was added to a ball mill jar, followed by 39.6g of nickel nitrate hexahydrate, 4.9g of cobalt nitrate hexahydrate, 0.6g of lanthanum nitrate hexahydrate, 1.8g of manganese nitrate tetrahydrate, and 2.4g of calcium nitrate tetrahydrate. The rest was the same as in Example 1. S200, the drying temperature is 80℃ and the time is 12h, the calcination temperature is 650℃ and the time is 5h, the rest is the same as in Example 1; S300, the reduction treatment temperature is 600℃, the time is 3h, and the rest is the same as in Example 1. Example 5

[0046] This embodiment provides a nickel-based supported multimetallic catalyst and its preparation method. The total loading of the multimetallic active components is 20.0 wt% by total catalyst mass, wherein the content of Ni is 15.0 wt%, the content of Co is 1.0 wt%, the content of La is 1.0 wt%, the content of Mn is 1.5 wt%, and the content of Ca is 1.5 wt%. The preparation method is basically the same as in Example 1, except that: In S100, 80.0 g of γ-Al2O3 was added to a ball mill jar, followed by 74.3 g of nickel nitrate hexahydrate, 4.9 g of cobalt nitrate hexahydrate, 3.1 g of lanthanum nitrate hexahydrate, 6.9 g of manganese nitrate tetrahydrate, and 8.8 g of calcium nitrate tetrahydrate. The rest was the same as in Example 1. S200, the drying temperature is 120℃ and the time is 6h, the calcination temperature is 700℃ and the time is 5h, the rest is the same as in Example 1; S300, same as Example 1. Example 6

[0047] This embodiment provides a nickel-based supported multimetallic catalyst and its preparation method. The total loading of the multimetallic active components is 5.0 wt% by total catalyst mass, wherein the content of Ni is 2.64 wt%, the content of Co is 1.32 wt%, the content of La is 0.26 wt%, the content of Mn is 0.39 wt%, and the content of Ca is 0.39 wt%. The support is SiO2. The preparation method is basically the same as in Example 1, except that: In S100, 95.0g of SiO2 was added to the ball mill jar, followed by 13.0g of nickel nitrate hexahydrate, 5.6g of cobalt acetate tetrahydrate, 0.8g of lanthanum nitrate hexahydrate, 1.8g of manganese acetate tetrahydrate, and 2.3g of calcium nitrate tetrahydrate. The rest was the same as in Example 1. Example 7

[0048] This embodiment provides a nickel-based supported multimetallic catalyst and its preparation method. The total loading of the multimetallic active components is 20.0 wt% by total catalyst mass, wherein the content of Ni is 12.0 wt%, the content of Co is 3.0 wt%, the content of La is 2.0 wt%, the content of Mn is 1.5 wt%, and the content of Ca is 1.5 wt%. The support is ZrO2, and the preparation method is basically the same as in Example 2, except that: In S100, 80.0g of ZrO2 was added to a ball mill jar, followed by 59.5g of nickel nitrate hexahydrate, 14.8g of cobalt nitrate hexahydrate, 6.2g of lanthanum nitrate hexahydrate, 6.9g of manganese(II) acetylacetone and 6.6g of calcium acetate monohydrate, with the remainder being the same as in Example 2. Example 8

[0049] This embodiment provides a nickel-based supported multimetallic catalyst and its preparation method. The total loading of the multimetallic active components is 20.0 wt% by total catalyst mass, wherein the content of Ni is 12.0 wt%, the content of Co is 3.0 wt%, the content of La is 1.5 wt%, the content of Mn is 2.0 wt%, and the content of Ca is 1.5 wt%. The support is MgO. The preparation method is basically the same as in Example 3, except that: S100. Add 80.0g of MgO to the ball mill jar, then add 59.5g of nickel nitrate hexahydrate, 14.8g of cobalt nitrate hexahydrate, 4.7g of lanthanum nitrate hexahydrate, 9.1g of manganese nitrate tetrahydrate and 8.8g of calcium nitrate tetrahydrate, the rest is the same as in Example 3.

[0050] Comparative Example 1 This comparative example provides a nickel-based supported multimetallic catalyst and its preparation method. The catalyst contains 10.0 wt% Ni by total mass, and the support is γ-Al₂O₃. The preparation method includes the following steps: S100. Add 90.0g of γ-Al2O3 to a ball mill jar, then add 49.6g of nickel nitrate hexahydrate, and the rest is the same as in Example 1 to obtain a single metal precursor powder. S200, same as in Example 1; S300, same as Example 1.

[0051] Comparative Example 2 This comparative example provides a nickel-based supported multimetallic catalyst and its preparation method. The catalyst contains 15.0 wt% Ni by total mass, and the support is γ-Al₂O₃. The preparation method includes the following steps: S100. Add 85.5g of γ-Al2O3 to a ball mill jar, then add 74.3g of nickel nitrate hexahydrate, and the rest is the same as in Example 1 to obtain monometallic precursor powder. S200, same as in Example 1; S300, same as Example 1.

[0052] Comparative Example 3 This comparative example provides a nickel-based supported multimetal catalyst and its preparation method. The formulation and preparation method are as shown in Example 1, except that: in S100, the Co precursor is not added, while the rest remain the same.

[0053] Comparative Example 4 This comparative example provides a nickel-based supported multimetal catalyst and its preparation method. The formulation and preparation method are as shown in Example 1, except that in S100, only Ni and Co are retained, that is, La, Mn and Ca are not added.

[0054] Comparative Example 5 This comparative example provides a nickel-based supported multimetal catalyst and its preparation method. The formulation and preparation method are as shown in Example 1, except that the ball milling time in S100 is 1 hour.

[0055] Comparative Example 6 This comparative example provides a nickel-based supported multimetallic catalyst and its preparation method. The formulation and preparation method are as shown in Example 1, except that the calcination temperature in S200 is 900℃ and the time is 6h.

[0056] Comparative Example 7 This comparative example provides a nickel-based supported multimetal catalyst and its preparation method. The formulation and preparation method are as shown in Example 1, except that in S300, the reduction temperature is 350℃ and the time is 2h, while the rest remain the same.

[0057] Performance testing Catalyst pretreatment: The catalysts obtained in Examples 1-8 and Comparative Examples 1-7 were pressed into tablets, crushed, and sieved to 20-40 mesh. 1.0 g of each tablet was weighed and packed into the isothermal zone of a fixed-bed quartz tube reactor, with both ends fixed with quartz wool. A 10% (v / v) H2 / N2 mixture was first introduced at a total flow rate of 100 mL / min. The temperature was increased to 650°C at 10°C / min and held for 3 hours to pre-reduce and activate the catalyst. After pre-reduction, the gas was switched to the test feed gas under an N2 atmosphere. Reforming reaction conditions: Biomass tar gas was used as the reforming feedstock, and the reaction temperature was 800℃; Analytical methods: After condensation and dehydration, the reaction tail gas was analyzed online using gas chromatography to determine the composition of gases such as H2, CO, CO2, and CH4. The H2 / CO molar ratio and syngas yield were calculated. The syngas yields and H2 / CO ratios of Examples 1-8 and Comparative Examples 1-2 are shown below. Figure 1 As shown; the tar content before and after the reaction was determined by solvent absorption combined with gas chromatography, and the tar removal rate was calculated using the following formula: Tar removal rate (%) = (Feed tar amount - Outlet tar amount) / Feed tar amount × 100%; The tar yield and tar removal rate of Examples 1-8 and Comparative Examples 1-2 are as follows: Figure 2 As shown; Carbon deposition performance test: After the reaction, the deactivated catalyst was subjected to thermogravimetric analysis (TG); under air atmosphere, the temperature was increased to 800℃ at 10℃ / min, and the carbon content on the catalyst surface was calculated based on the sample weight loss to evaluate the anti-carbon deposition performance of different catalysts.

[0058] Table 1 As shown in Table 1, the nickel-based supported multi-metal catalyst prepared by ball milling in this invention exhibits superior overall reaction performance in the biomass tar gas reforming reaction. Compared with the single-metal Ni catalyst, the multi-metal catalyst is generally superior in terms of tar removal rate and H2 / CO ratio, indicating that the introduction of Co, La, Mn, and Ca is beneficial to improving the Ni-based catalyst's ability to crack and convert complex tar components and the quality of the produced gas. The nickel-based multi-metal synergistic system of this invention can effectively suppress the formation of carbon deposits during the biomass tar gas reforming process. Compared with the single-metal Ni catalysts shown in Comparative Examples 1 and 2, the amount and rate of carbon deposits after the reaction in Examples 1-8 are generally lower, indicating that the multi-metal synergistic design is beneficial to reducing the deposition of carbon deposit precursors on the catalyst surface during tar cracking.

[0059] Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A nickel-based supported multimetal catalyst, characterized in that, The catalyst includes an oxide support and a multi-metal active component supported on the surface and / or within the pores of the oxide support; The oxide support includes at least one of aluminum oxide, silicon oxide, zirconium oxide, magnesium oxide, and composite oxides. The multimetallic active component includes Ni, and at least one of Co, La, Mn and Ca.

2. The nickel-based supported multimetal catalyst according to claim 1, characterized in that, The carrier includes Al2O3.

3. The nickel-based supported multimetal catalyst according to claim 1, characterized in that, The multimetallic active components include Ni, Co, La, Mn, and Ca.

4. The nickel-based supported multimetal catalyst according to claim 1, characterized in that, The total loading of the polymetallic active components is 5-20 wt% based on the total mass of the catalyst.

5. The nickel-based supported multimetal catalyst according to any one of claims 1 to 4, characterized in that, Based on the total mass of the catalyst, the content of Ni is 2~15wt%, the content of Co is 1~5wt%, the content of La is 0.2~2wt%, the content of Mn is 0.2~2wt%, and the content of Ca is 0.2~2wt%.

6. A method for preparing a nickel-based supported multimetallic catalyst according to any one of claims 1 to 5, characterized in that, Includes the following steps: S100. The oxide carrier and the multi-metal precursor are added to a ball milling device and mixed by ball milling under the action of grinding media to obtain precursor powder. S200. The precursor powder is dried and calcined to obtain a supported multi-metal precursor catalytic material. S300. The supported multi-metal precursor catalyst material is reduced to obtain the nickel-based supported multi-metal catalyst. The multi-metal precursor includes a Ni precursor, and at least one of a Co precursor, a La precursor, a Mn precursor, and a Ca precursor.

7. The preparation method according to claim 6, characterized in that, In S100, The ball milling mixing speed is 100~600 rpm, and the time is 3~9 hours; The grinding media is a combination of one or more grinding balls with different particle sizes; The ball milling mixing mode employs an alternating combination of forward rotation, stop rotation, and reverse rotation.

8. The preparation method according to claim 6, characterized in that, In S200, The drying process is carried out at a temperature of 80~120℃ for 6~12 hours. The calcination treatment is carried out at a temperature of 500~800℃ for 4~6 hours.

9. The preparation method according to claim 6, characterized in that, In S300, the reduction treatment is carried out at a temperature of 400~800℃ for 2~4 hours.

10. A method for producing syngas through reforming, characterized in that, A carbon-containing raw material is fed into a reactor and reformed under the action of a nickel-based supported polymetallic catalyst as described in any one of claims 1 to 5 to obtain syngas; wherein the carbon-containing raw material includes at least one of tar, pyrolysis gas, and biomass-derived oxygen-containing organic matter.

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