Fundamentals of Catalytic Hydrodechlorination of CFCs

摘要：CTS-9509580本研究的目的是在工业相关条件下，将加氢脱氯过程中碳-氯键解离的能量学与催化剂性能联系起来。这是一项合作成果，结合了卡内基梅隆大学对钯反应动力学的表面科学测量（111），以及匹兹堡大学对负载钯颗粒在常压下催化的反应研究。一套共同的选择性氟化氯甲烷和氯乙烷用于连接表面科学和催化研究。两项研究都测量了吸附热、表观活化能、本征活化能和速率常数。利用线性自由能关系确定碳-氯键解离是均解还是异解，并预测改性剂的影响。这是一项关于将氯氟烃（CFCs）转化为氢氟碳化合物（hfc）的研究。研究结果同样适用于氯碳在低温下的破坏。因此，该研究对制冷剂和发泡剂的生产以及清洗剂的环境管理都有直接的影响。

ABSTRACT CTS-9509580 The objective of this effort is to relate the energetics of carbon-chlorine bond dissociation in hydrodechlorination to catalyst performance under industrially relevant conditions. This is a collaborative effort combining surface-science measurements of reaction kinetics on palladium (111), done at Carnegie Mellon University, with reaction studies at atmospheric pressure catalyzed by supported palladium particles, performed at the University of Pittsburgh. A common set of selectively fluorinated chloromethanes and chloroethanes serves to link the surface-science and catalytic investigations. Both studies measure heats of adsorption, apparent activation energies, intrinsic activation energies, and rate constants. Linear free-energy relationships are used to determine whether carbon-chlorine bond dissociation is homolytic or heterolytic, and predict the effects of modifiers. This is a study of the conversion of chlorofluorocarbons (CFCs) into hydroflourocarbons (HFCs). The results are also applicable to the destruction of chlorocarbons at low temperature. Thus the study has direct impact both on the manufacture of refrigerants and blowing agents and on the environmental management of cleaning agents.