The Study Of CuO/ZnO/CeO₂/ZrO₂ Catalyst Supported On SiC Porous Ceramic And Its Methanol Steam Reforming For Hydrogen Production

Proton exchange membrane fuel cells（PEMFCs）have good application prospects in the field of transportation due to their advantages of fast startup,high power density,and high reaction efficiency.However,PEMFC uses high-purity hydrogen as fuel,which leads to high fuel cost,and at the s ame time brings about safety problems in hydrogen transmission,hydrogen storage and hydrogen supply,and high hydrogen fuel infrastructure construction costs.The hydrogen production technology of methanol steam catalytic reforming based on porous supports is expected to solve the safety problem of hydrogen energy storage and transportation by realizing the instant preparation of hydrogen,and it is a hydrogen production technology with great development potential.Porous Si C ceramics with good chemical stability,corrosion resistance,high mechanical strength and good thermal conductivity are ideal catalyst carriers for methanol steam reforming at high temperature.Cu-based catalysts are the most widely used catalyst systems in the methanol steam reforming（MSR）reaction system.They have the characteristics of high catalytic activity and low cost.However,they are unstable and difficult to suppress CO production in the long-term reaction process.insufficient.Therefore,in this paper,Si C porous ceramics are used as catalyst supports and microchannels for reforming hydrogen production reaction,and ZnO,CeO₂ and ZrO₂ components are introduced on the basis of Cu-based catalysts,and CuO/ZnO/CeO₂/ZrO₂ catalysts are formed by comparing different preparation methods.Porous ceramics are coupled with CuO/ZnO/CeO₂/ZrO₂ catalysts to carry out research on hydrogen production from methanol steam reforming.The main research contents and results are as follows:（1）The effect of the precipitant concentration of the co-precipitation method on the particle size,morphology,phase composition,reducibility and specific surface area of the catalyst was systematically studied,CuO/ZnO/CeO₂/ZrO₂ catalysts with small particle size,uniform distribution and low reduction temperature were obtained at lower precipitant concentration.The CuO/ZnO/CeO₂/ZrO₂-Si C catalytic reactor obtained by the co-precipitation method was tested by the MSR hydrogen pro duction platform,which showed that it had less carbon deposition and good catalytic stability.Under the optimized reaction conditions（the reaction temperature was 280°C,and the reactant supply rate was 5 m L/h）,the H ₂ content in the gaseous product was 73.16%,and the CO content was 1.96%.（2）The CuO/ZnO/CeO₂/ZrO₂ catalyst with the same composition as the coprecipitation method was prepared and supported on Si C ceramics by the solution combustion method.The results showed that the particle size of th e catalyst obtained by the solution combustion method was smaller and more distributed than that by the coprecipitation method.evenly.The MSR hydrogen production platform test shows that the catalyst prepared by the solution combustion method has lower carbon deposition and better catalytic stability.The H₂ content was 73.98%and the CO content was 1.60%.（3）CuO/ZnO/CeO₂/ZrO₂ catalysts with the same composition were further prepared by inverse microemulsion method,and the particle size and distribution uniformity of the catalysts were further optimized.Under the optimized reaction conditions for hydrogen production（the reaction temperature is 280°C,and the supply rate of the reactants is 5 m L/h）,the H₂ content is increased to 75%,and the CO content is reduced to 0.24%.After 160 hours of catalytic reaction,the methanol conversion rate is still as high as 98%.