Active Phase Design And Modulated Research Of Au Catalyst For Acetylene Hydrochlorination

Polyvinyl chloride?PVC?are widely used in various aspects of society,and the vinyl chloride is monomer.According to the principle of the preparation,the preparation way of vinyl chloride divided into acetylene method and ethylene method.For our country,its many coal oil less natural resources conditions decide the acetylene method is dominant way of vinyl chloride preparation.Industrial acetylene method use mercuric chloride catalyst on loading on activated carbon.Mercuric chloride resources are exhausted,and the has a huge harm of human body and environment,coupled with the nature of the volatile of it.So it is need to find proper catalytic systems to replace the mercury to catalyzed hydrogen chloride reaction.Gold catalyst itself due to the high standard electrode potential.so it is a efficient catalytic for acetylene hydrogen chloride.Gold catalyst has been recognized both at home and abroad is suitable for the new type catalyst instead of mercury.But the gold catalyst activity center Au³⁺was easy reduced to Au⁰,and loading on the activated carbon can easy formation carbon deposition.In addition gold load too high will cause the huge costs of production.So it is an urgent need to improve the catalyst performance to inhibit the reduction of Au³⁺and carbon deposition,and reduce the load of as much as possible.Ca^II as additives of the preparation of Au-Ca^II/AC bimetallic catalyst can effectively improve the gold catalytic activity and stability of the catalyst.Au capacity of 0.5 wt%,Ca^II load of 1.5 wt%.In the reaction condition of T=180?,GHSV=370h^-1,V?HCl?/V?C₂H₂?=1.2,Acetylene conversion of Au-Ca^II/AC higher than single gold catalyst at least 30%.In the 50 h reaction time,C₂H₂ conversion only decreased by 0.63%.Because the Ca^II additives adding a effective catalyst surface area of carbon formation,prevent the aperture of congestion and increase the number of surface active sites.In^III as the second additives added into Au-Cs^I/AC bimetallic catalyst,through the synergy between the two additives,together with the Au formed three metal alloy structure.We were prepared the Au-In^III-Cs^I three metal catalytic system.Au,In^III,Cs^I capacity respectively is 1 wt%,1 wt%,4 wt%.In the reaction condition of T=180?,GHSV=1480 h^-1,V?HCl?/V?C₂H₂?=1.2,Three metal catalysts in the evaluation of 50h time,the acetylene conversion was only reduced from the original 92.8%to 89.1%.The promotion of activity and stability because of the Cs^I and In^III inhibits reduced of Au³⁺,and effectively curb carbon deposition of catalysts.The electron was transferred from In^III to the Au³⁺,make its electronegativity enhanced,and strengthen the adsorption of reactant HCl and C₂H₂.Through the introduction of IL,we was prepared to design new active phase[Prmim]AuCl₄ from the molecular level.The Au capacity of Au-IL/AC catalyst was only 0.1 wt%.In the reaction condition of T=180?,GHSV=370 h^-1,V?HCl?/V?C₂H₂?=1.2,The acetylene conversion level is greater than 72.1%within 12h.and the TOF value is 4.5 times that of the Au catalysts.New active phase can be better stable Au³⁺species,improved the Au dispersion and utilization.So can efficient catalyst acetylene hydrogen chloride.