本文针对柴油车尾气中碳烟颗粒污染环境的问题,综述了国内外关于碳烟颗粒催化消除及其作用机理的研究进展.指出了转换频率(TOF)更能从真正意义上表征催化剂的内在活性,从而有利于认识真实的反应机制和开发更高活性的催化剂.基于碳烟催化燃烧技术的特点和存在的问题,对今后相关的研究工作进行了展望.
Diesel engines have attracted increasing attentions due to their high power,high durability and low maintenance cost.Therefore,they have been successfully installed on light-duty passenger cars as well as heavy-duty trucks and engineering plants.Compared with gasoline engines,the diesel engines possess better fuel efficiency with lower emission of carbon oxides and hydrocarbon due to the high compression ratio and relatively high O2 concentrations in the diesel combustion chamber.However,a large amount of soot are emitted under such condition and they have caused serious environmental problems,such as photochemical smog,acid rain and some human diseases like asthma.As the legislation becomes more and more stringent,it is urgent to eliminate this hazardous material.Among the soot removal technologies,DPF is proved to be an efficient way,in which catalysts are used to lower the soot combustion temperatures leading to the continuous regeneration of the filter.Therefore,more and more researchers have made great efforts to study the catalytic process for soot elimination.In this work,the latest research progresses in China and abroad on the relevant catalysts and catalytic reaction for the soot combustion process are reviewed.Emphases were focused on the soot catalytic removal technologies,the soot catalytic removal catalysts and catalytic process,as well as soot catalytic removal mechanisms.Additionally,it is proposed that the real reaction activity can be evaluated more precisely based on TOF,thus the realistic reaction mechanisms can de deduced.Finally,based on the feature and existing difficulties which are present in the soot catalytic combustion technology,and from the view of commercialization,future developments in this field are prospected.