Studies On Reforming Reactions Of Methane To Syngas

It's a very important way of effective utilization of natural gas about the variable critical chemicals produced by syngas which derives from methane reforming with carbon dioxide or bi-reforming with carbon dioxide and water.The main reason that this reaction hasn't been applied in industry is for now,a highly stable,highly active and cheap catalyst hasn't been found yet.This thesis is mainly about this topic,and it's based on the traditional catalysis theory,through the reasonable design and synthesis,an applicable catalyst that can endure the harsh reaction conditions while maintain the high activity and stability.It has laid a bit foundation to the real application of these series reactions in industry.Hence,the main work is as follows:1.The main reasons to deactivate the catalyst are the sintering of the active sites and the coke deposition on the active sites and the support.To solve these problems,through the detailed analysis about the physical chemical mechanism,the according solution is raised.First of all,the CuNi alloy nanoparticles are synthesized and distribute on ?-Al₂O₃ support to suppress the coke deposition on the active sites.The experiments results prove that the alloys can effectively suppress the coke deposition on the active sites,and then make the catalyst more stable in long-term experiments.Next,before depositing the alloy nanoparticles,ZrO₂ is decorated on the alumina support in advance to suppress the coke deposition on the support and weakens the interaction between the alumina support and Cu in the alloy to stabilize the alloy structure.At last,after distributing the alloy nanoparticles,ZrO₂ is covered second time.The partially covered ZrO₂ on CuNi nanoparticles can avoid the sintering problem.The experiments results show that the catalyst designed through the above procedures can maintain the long-term high activity and stability in methane reforming with carbon dioxide reaction.2.In the real experiments,the syngas ratio?H₂/CO?is less than 1 because of the reverse water gas shift reaction,which is not suitable for the subsequent reactions.Through introducing water into the reaction system as it can be called bi-reforming to make the syngas ratio to be controllable.Based on the above results,this thesis also talks about the catalytic ability of CuNi alloy catalyst decorated by ZrO₂ in the methane bi-reforming reaction.It is proved that this catalyst can withstand the high reaction temperature with the existence of water and maintaining the high activity and stability.Through various characterization methods,the catalyst structure and its changing process are demonstrated and these results mean a lot to the real application of this catalyst.