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The Application of Supercritical Fluids in Catalytic Reaction Tang Haodong, Lu Chunshan, Guo Haiguang, Han Wenfeng, Liu Huazhang Abstract Supercritical fluids possess unique properties
(e.g. gas-like transport properties, liquid-like dissolving power and heat capacities)
that make them highly applicable in catalytic reaction. According to the mechanism and
characteristics of their application in catalytic reaction, supercritical fluids were
utilized in the following three ways: (1) use supercritical fluids to dissolve all the
reactants, sometime even including catalyst, into one single phase owing to their unique
miscibility. This eliminates the limitation of inter-phase mass transfer, and increases
the rate of reaction; (2) prolong the lifetime of catalyst through in situ extracting and
removing in time coke precursors that can poison the catalyst from the catalyst surface,
using supercritical fluids' gas-like diffusibility, liquid-like density and unique
miscibility; (3) increase the selectivity and the rate of reaction due to the clustering
effects between solute and solvent, and between solvent and solvent in supercritical
fluids. Besides, some typical reactions concerning the application of supercritical fluids
in catalytic reactions in recent years are also introduced.
唐浩东 卢春山 国海光 韩文锋 刘化章 摘要
由于超临界流体拥有类似气体的传递特性及类似液体的溶解能力和热容的独特性能，使其在催化反应中具有很大的应用潜力。本文根据超临界流体在催化反应中应用的机理和特性将其应用分成三大类：(a)利用超临界流体独特的溶解性能，将反应物甚至催化剂溶解在同一相中，消除相间的传递限制，提高反应速率；(b)利用超临界流体具有类似气体的扩散特性、类似液体的密度和独特的溶解性能，从催化剂表面原位萃取并及时带走能导致固体催化剂中毒的焦炭前驱体，延长催化剂的寿命；(c)利用超临界流体中溶质与溶剂、溶剂与溶剂之间存在的较强集聚(clustering)作用，提高反应的选择性同时增加反应速率。本文还介绍了近年来超临界流体在催化反应中应用的典型反应。 唐浩东 男，28岁，讲师，主要从事催化及超临界反应等方面的研究。 |