LT: Heterogeneous Catalysis in Supercritical Carbon Dioxide

9873553亚伯拉罕许多商业化学合成是在有机液体溶剂中使用均相催化剂进行的。有机溶剂的大规模使用受到了长期环境影响的质疑。本研究的目的是探索超临界二氧化碳作为环境友好的反应溶剂的用途，特别是它在丙烯氢甲酰化反应中的应用。使用二氧化碳作为反应溶剂提供了最佳的环境性能，因为二氧化碳不会消耗臭氧层，不会造成地面烟雾，也不会导致全球变暖。由于溶解度的限制，目前的均相催化剂不太可能充分溶解到在二氧化碳中有效。建议使用多相催化，通过省去催化回收步骤，并允许在简单的填充床反应器中进行反应，从而简化下游操作。为了证明聚丙烯氢甲酰化反应可以在超临界二氧化碳中完成，并证明基于该技术的工艺具有环境优势和经济竞争力，研究人员将(1)选择已成功用于气相氢甲酰化反应的多相催化剂，并测试这些催化剂在超临界二氧化碳中的活性；(2)确定二氧化碳对反应机理的影响及其在控制产品选择性和丙烯转化率方面的作用。这笔赠款是根据NSF/朗讯技术工业生态研究奖学金计划1998年联合进行的。*

9873553 Abraham Many commercial chemical syntheses are carried out in organic liquid solvents using homogeneous catalysts. The large-scale use of organic solvents has been questioned with respect to long-term environmental impacts. The objective of this research is to explore the use of supercritical carbon dioxide as an environmentally benign reaction solvent, and in particular, its use for the hydroformylation of propylene. The use of CO2 as a reaction solvent offers optimal environmental performance because CO2 does not deplete the ozone layer, does not contribute to ground level smog and will not contribute to global warming. Because of solubility limitations, it is unlikely that current homogeneous catalysts can be made sufficiently soluble to be effective in CO2. The use of a heterogeneous catalysis is proposed and that will also simplify the downstream operations by eliminating the catalysis recovery step and allowing the reaction to be performed in a simple packed bed reactor. In order to demonstrate that hydroformylation of polypropylene can be accomplished in supercritical CO2 and that a process based on this technology is environmentally superior and economically competitive with current technology, the researcher will (1) prepare selected heterogeneous catalysts that have successfully been used for vapor phase hydroformylation and test these catalysts for their activity in supercritical carbon dioxide and (2) determine the impact of CO2 on the reaction mechanism and its role in controlling the product selectivity and the rate of propylene conversion. This grant is made pursuant to the joint NSF/Lucent Technologies Industrial Ecology Research Fellowships Program 1998.***