Study On Deactivation Behavior And Modification Of Cu Catalyst For Acetylene Hydrochlorination

Polyvinyl chloride?PVC?manufactured more than 40 million tons every year worldwide as one of most prevalent material of plastics.Vinyl chloride?VCM?is the monomer for industrial production of polyvinyl chloride.The reaction of acetylene hydrochlorination widely used to product VCM in great majority developing countries,such as China.Commercial catalyst mercuric chloride?HgCl₂?-impregnated activated carbon?AC?characterized volatility and toxic can sublimation into the environment poses a threat to many organisms.With the urgent need of green life,it has become one of the important responsibilities of chemical workers to find a green cheap non-mercury catalyst.Au-based catalysts appear superior performance.However,the major challenges hampering Au-based catalysts towards its practical applications are the high cost and fast deactivation.There is a lack of solutions to maintain or enhance catalyst performance while reduced or remove Au content in catalyst.In this paper,the research object of active site is green and cheap Cu.The deactivation behavior of Cu/AC catalyst was systematically studied and several possible inactivation reasons of Cu/AC are analyzed.Characterization and analysis of catalysts before and after deactivation,the reason of deactivation is to generate Cu₂?OH?₃Cl chloride species,the behavior of carbon deposition can also lead to partial inactivation.It was further verified that Cu₂?OH?₃Cl was a deactivated species by direct preparation of supported Cu₂?OH?₃Cl catalyst.What's more a method for regeneration of deactivated catalyst by re-impregnation of hydrochloric acid has been found.Study on the modification of Cu/AC with additives of non-precious metal Cs and the structure of perovskite-like CsCuCl₃ over Cu-Cs/AC catalyst was constructed and demonstrated.This Cu-Cs/AC catalyst exhibits high activity than pure Cu catalyst,which also shown great long-term stability with C₂H₂ conversion remains constant??92%?over 200 h.The conversion of 3Cu-Cs/AC catalyst can reach 95%which is also superior to the commercial HgCl₂/AC catalyst,suggesting a great prospective of industrialization.While maintaining the essential advantages of cheap and economical copper catalyst,the performance of the catalyst is improved.