碳负载二价金属催化剂RCl_2/C催化氯乙烯合成反应机理

Mechanism of synthesis of vinyl chloride catalyzed by carbon load bivalent metal catalyst RCl_2/C: a density functional theoretical study

聚氯乙烯具有诸多性能,在工业中应用广泛.聚氯乙烯是由氯乙烯单体发生聚合反应而制得的,氯乙烯工业生产过程涉及催化剂活性、催化剂载体以及催化剂中毒效应的相关研究.本文利用石墨烯模拟活性炭结构表面的活性位,研究了不同二价金属催化剂RCl2/C(R=Hg2+、Pt2+、Cu2+、Pd2+、Mg2+、Cd2+)在碳负载条件下对乙炔氢氯化反应的催化机理以及可行的反应通道.通过比较不同路径的速控步骤的活化能大小,确定了最优反应通道,同时也发现了新频的反应通道.进一步分析了每种催化剂的催化活性与其微观特性之间的关系,以及反应活化能与催化剂能隙的关系.此外,还考察了系列催化剂的中毒效应,通过综合比较系列催化剂的作用特征,从理论上对氯乙烯合成催化剂进行了优化,也为氯乙烯工业生产提供了有益的信息.

Polyvinyl chloride is widely used in industry due to its many properties, and polyvinyl chloride is produced by the polymerization of vinyl chloride monomer. The process of production of vinyl chloride is related to catalyst activity, catalyst carrier and catalyst poisoning effect. In this paper, by using graphene to simulate the surface of activated carbon structure surface, the catalytic mechanism and the feasible reaction channels of synthesis for vinyl chloride catalyzed by RC12/C （R=Hg^2 ＋, Pt^2 ＋, Cu^2 ＋, Pd^2 ＋, Mg^2 ＋, Cd^2＋） were theoretically studied under the carbon load conditions. By comparing the activation energy of the velocity control steps of different paths, the optimal reaction channel was determined, and the new reaction channels have been found. Furthermore, the relationship between the catalytic activity of each catalyst and its microscopic properties was analyzed, and the relationship between the reaction activation energy and energy gap of catalyst was also discussed. At the same time, we have studied the poisoning effect of the series of catalysts, and the synthesis catalyst of vinyl chloride was optimized by comparing the characteristics of series catalysts. The results of some experiments are well explained from this work, and our results also provide useful information for the production of vinyl chloride industry.