CAREER: Environmentally Benign Chemical Processing: A Theme for the Future of Chemical Engineering

研究的重点是通过催化加氢脱氯将氯氟烃(CFCs)转化为对环境更友好的氢氟烃(HFCs)的新工艺的开发。研究的初始模型是不同材料负载的钯催化1，1-二氯四氟乙烷的加氢脱氯反应。重点阐明了决定1，1，1，2-四氟乙烷选择性的因素。定量速率测量提供了基本的动力学参数，如吸附热、活化能和本征速率常数。确定了金属颗粒大小、金属-载体相互作用和载体酸度对这些参数的影响。用同位素瞬变实验和线性自由能关系研究了该反应的机理和过渡态。这项研究的结果对于销毁工业废物中的氯氟烃、控制氯氟化碳排放以及生产环境更可容忍的替代制冷剂、清洗剂、发泡剂和推进剂具有重要意义。这项研究同时开发了课堂课程和实验室实验两种形式的课程材料。本科生和研究生都能接触到无害环境的化学加工的概念和目标。其目的是灌输新的工程实践标准，包括承认环境问题和需求。

ABSTRACT Julie d'Itri The focus of the research is the development of new processes for conversion of chlorofluorocarbons (CFCs) to environmentally more benign hydrofluorocarbons (HFCs) by catalytic hydrodechlorination. The initial model under investigation is the hydrodechlorination of 1,1- dichlorotetrafluoroethane catalyzed by palladium supported on various materials. Emphasis is placed on elucidating the factors that dictate selectivity towards 1,1,1,2- tetrafluoroethane. Quantitative rate measurements provide fundamental kinetics parameters such as heat of adsorption, activation energy, and intrinsic rate constant. The influences of metal particle size, metal-support interactions, and support acidity on each of these parameters are determined. The mechanism and transition state are examined using isotopic transient experiments and linear free energy relationships. The results of this research are important for the destruction of chlorofluorocarbons in industrial wastes, for control of CFC emissions, and for the production of substitute refrigerants, cleaning agents, blowing agents, and propellants that are more tolerable environmentally. Curricular materials in the forms of both classroom courses and laboratory experiments are developed in tandem with this research. Students at both undergraduate and graduate levels are exposed the concepts and goals of environmentally benign chemical processing. The intent is to instill new standards of engineering practice that include recognition of environmental concerns and needs.