低温等离子体制备低碳醇合成用KNiMo基催化剂及其结构性能表征

Preparation of KNiMo-based catalysts by using non-thermal plasma and their catalytic performance in the synthesis of higher alcohols from syngas

采用低温等离子体法在温和条件下制备了低碳醇合成(HAS)用的高性能KNiMo基催化剂,利用XRD、氮吸附、TEM、H_2-TPD、CO-TPD和原位CO吸附DRIFTS等技术对其进行了表征。结果表明,与传统的热法制备相比,低温等离子体法不仅缩短了制备时间,而且得到的KNiMo基催化剂层数少、粒径小、分散度高,有利于形成更薄和更短的片层,并暴露大量位于边、角位的催化活性位,促进CO转化和醇的形成,表现出优异的低碳醇合成催化性能。其中,采用低温等离子体直接制备的KNiMo-DPS催化剂,在5 MPa、350℃、空速为5000 h^(-1)的反应条件下,CO转化率达到32.3%,总醇选择性为75.1%,总醇中C_(2+)醇的选择性为65.2%。

A series of KNiMo-based catalysts were prepared by using non-thermal plasma and characterized by XRD,nitrogen sorption, TEM, H2-TPD, CO-TPD, and in-situ CO adsorption DRIFTS;their catalytic performance in the higher alcohol synthesis( HAS) from syngas was investigated. The results indicate that in comparison with those prepared by the conventional thermal method,the KNiM o-based catalysts prepared by using non-thermal plasma display thinner and shorter MoS2 slabs and more highly dispersed and coordinatively unsaturated sites,which endowthe KNiM o-based catalysts excellent performance in HAS. In particular,for the HAS over the KNiM o-DPS catalyst under 350 ℃,5 M Pa,and a gas hourly space velocity( GHSV) of 5000 h^-1,the conversion of CO reaches 32.3%,with a selectivity of 75.1% to total alcohol and a C2+ alcohol selectivity of 65.2% in the total alcohols.