CAJ | 학술논문

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.
유우초림계류체옹유유사기체적전체특성급유사액체적용해능력화열용적독특성능,사기재최화반응중구유흔대적응용잠력.본문근거초림계류체재최화반응중응용적궤리화특성장기응용분성삼대류:(a)이용초림계류체독특적용해성능,장반응물심지최화제용해재동일상중,소제상간적전체한제,제고반응속솔;(b)이용초림계류체구유유사기체적확산특성、유사액체적밀도화독특적용해성능,종최화제표면원위췌취병급시대주능도치고체최화제중독적초탄전구체,연장최화제적수명;(c)이용초림계류체중용질여용제、용제여용제지간존재적교강집취(clustering)작용,제고반응적선택성동시증가반응속솔.본문환개소료근년래초림계류체재최화반응중응용적전형반응.
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.