The Catalytic Performance Study Of Cu Co And Fe Based Catalysts For Acetylene Hydrochlorination

Polyvinyl chloride?PVC?was widely used in various fields.PVC is produced from the polymerization of vinyl chloride monomer?VCM?.The acetylene-based method is the primary VCM production method in China for the country's vast domestic coal resources.Acetylene hydrochlorination reaction is the most important step in the acetylene-based method.However,the mercury-based catalyst?HgCl2/AC?is an obstacle in the current industrial production of VCM.HgCl2 causes not only the deactivation of the catalyst but also serious damage to human health and environmental pollution.As mercury resources dwindling and the global mercury pollution prevented and control policy initiatived.Thus,exploring environmentally friendly non-mercury catalysts for acetylene hydrochlorination is necessary.Numerous attempts have been made to develop a non-mercury catalyst for a long time.And the research has been made some progress.In previous reports,the activity of precious metal catalyst has higher catalytic performance;however,high cost,easy reduction is the limiting factor for their industrial applications.Non-noble metal catalysts have gradually becoming the object of the researchers to explore.Our target is mainly researching the economic environmentally friendly non-noble metal catalysts.The main research content is as follows:1.Explore catalytic performance of the non-noble metal catalyst Cu-g-C3N4/AC in the acetylene hydrochlorination reaction.The test results indicate that the acetylene conversion of the Cu-g-C3N4/AC catalyst was 79%?T=180 ?,V?HCl?/V?C2H2?=1.15,GHSV?C2H2?=72 h-1?,and the acetylene conversion almost remain the same after reaction 450 min.TEM,XRD and XPS results proved that the introduction of CuCl2 to the g-C3N4/AC catalyst increased the relative pyrrolic N content,and enhanced the adsorption capacity of HCl.Moreover,the existence of CuCl2 inhibits partly coke deposition on the catalyst.2.Explore the catalytic performance of the cobalt-based catalyst?Co-N-AC catalyst and Co-P-AC catalyst?in the acetylene hydrochlorination reaction.These two kinds of catalysts were made by impregnation and calcination method.Tests results revealed that the highest conversion of the Co-N-AC catalyst was 66% which is better than N-AC and Co-AC catalyst.TEM,TPD,XPS analysis found that Co-N-AC catalyst can greatly improve the adsorption ability of HCl,and the Co-Nx groups in the catalyst may be playing an important role in improving acetylene hydrochlorination reactivity.XRD,BET and XPS analysis results proved that the Co and P were doped on the AC,it also found that the existence of the Co-P group in the Co-P-AC catalyst.Test results show that the highest acetylene conversion of the Co-P-AC catalyst was 36%.3.Explore the catalytic performance of two different types of iron-based catalyst?Fe-N-AC and Fe₃C-N-C?in the acetylene hydrochlorination reaction.The Fe-N-AC catalyst used impregnation and calcination method for preparation was characterized by BET,XRD and XPS.The results show that there are pyridine-type nitrogen,pyrrole-type nitrogen,graphite-type N and Fe-coordinated nitrogen in the Fe-N-AC catalyst.Test results?T=180?,V?HCl?/V?C2H2?=1.15,GHSV?C2H2?=36h-1?show that the acetylene conversion of the Fe-N-AC catalyst is only 45%,which is lower than the corresponding N-AC?60%?.Fe₃C-N-C catalyst is made up of urea,glucose and ferric nitrate by high temperature calcination.The Fe₃C-N-C was characterized by BET,XRD and XPS.The results show that there are Fe₃ C nanoparticles and three different types of nitrogen in the catalyst.The acetylene conversion of the Fe₃C-N-C catalyst is only 36%.