Fischer-Tropsch合成烃生成机理研究进展

Fischer-Tropsch合成烃生成机理研究经历本体碳化物机理，烯醇机理和CO插入机理后，重新回到碳化物机理。但后者不同于早期的本体碳化物机理，新碳化物机理认为，催化剂表面亚甲基的生成与催化剂本体金属碳化物的生成无关，由于F－T反应生成的烯烃在催化剂上发生再吸附并引起二次反应，所以F－T合成产物选择性由一次和二次反应共同决定，由于现有的机理仅考虑了一次反过程，为弥补其缺陷，本文在综述前人的F－T反应机理基础上，补充了包括二次反应的F－T反应机理，在该机理中添加了烯烃再吸附及二次反应的可能方式。

ADVANCE IN HYDROCARBON FORMATION MECHANISM OF FISCHER-TROPSCH SYNTHESIS

After the bulk carbide mechanism, the enol mechanism and the CO insertion one, a new carbide mechanism has been re accepted and considered as the best mechanism for the explanation of hydrocarbon formation during the Fischer Tropsch synthesis The new carbide mechanism is different from the old carbide one The former assumes that the formation of surface methylene species has no relation with the metal carbides formed in the catalyst bulk Three branches of the carbide mechanism of the Fischer Tropsch synthesis are specially reviewed in this paper Because the formed alkenes during the Fischer Tropsch synthesis will re adsorb on the catalysts, which will leads to secondary reactions, both primary reactions and secondary ones determine the selectivity of hydrocarbon product However, the available mechanisms only concern the intrinsic or primary reaction pathways On the basis of the previous carbide mechanisms of the Fischer Tropsch synthesis, the possible ways of alkene readsorption and possible pathways of secondary reactions are proposed in the paper, which remedies the defect of the available Fischer Tropsch reaction mechanisms