Effect Of Preparation Technology In Catalytic Behavior For HgCl2Catalyst

In this work, based on mercuric catalyst, the preparation process were mainly research.Problems involved on the characterization、preparation process of influencing factors、 thespeciation of mercury on mercury catalyst and the reaction mechanism are discussed in detai toprovided technical support for the preparation of ultra low mercury catalyst.First of all, A series of characterizations as XRD and BET were utilized to reveal thetextural and structural properties for the catalyst from the factory. Results showed that thespecific surface area、pore structure of catalyst and the dispersion and uniformity of the catalystsurface active component has gerat influence for the performance of the catalyst. Thecharacterization results also identified a simple and effective method for the characterization ofthe catalyst and provided the characterization methods for the catalyst preparation..Secondly, this paper examines the impact of water content on the catalyst performance forthe catalyst performance.Characterizes it by several methods, and the results indicated that there are noessential influence on the catalyst when the water content on the catalyst increased, but the catalystsprepared by different drying methods have different characteristic. The active component maytransfered to external from the catalysts and precipitated in the orifice. Therefore, in the processof of catalyst preparation, the choice of appropriate drying way is also very important.Then, this paper discussed the effect of the preparation process with the KCl as catalystadditives. Research results show that the addition of KCl can reduce the adsorption ability ofactivated caron adsorption of mercuric chloride. But KCl will react with activated carbon andmercuric chloride to raise the decomposition temperature of20~40℃, and enhancement thecatalyst stability. Therefore, in the preparation processof catalyst, adding KCl as catalyststabilizer can prevent the loss of active components.The the sample characterization showed that there were existenced mercuric chloride in catalyst, so in this paper, we designed experiments to analyse the existing forms and the relativecontent of mercury in the catalyst. The experimental results show that, in the catalyst not onlyhas the presence of mercury chloride, and the relative content of mercurous chloride reachesabove40%. Therefore, during the in the preparation processof catalyst, we should develop newpreparation method, such as the mechanical mixing method or the gas phase adsorption methodto reduce the amount of change of mercuric chloride. The studies will provide the possibility forthe preparation of super low mercury catalyst.The adsorpivity and reaction performance of acetylene, hydrogen chloride and vinylchloride on the suiface of mercuric chloride catalyst has been studied by in-situ infrafedspectroscopy technique. The results showed that hydrogen chloride preferentially adsorbed onthe catalyst, and the adsorbed hydrogen chloride was formed. Then the C2H2was activated by theinteraction between the HgCl2and C2H2. The chlorovinyl, which adsorbed on the catalyst, wasformed by the reaction of the activated C2H2and adsorbed HCl. The conclusion from this studywill provide a theoretic basis on the experimental design of the low mercury catalysts with highperformance.