钾对高硫合成气制甲硫醇磷钼基催化剂的影响

doi:10.11944/j.issn.1000-0518.2016.09.160021

摘要/Abstract

摘要：

采用等体积共浸渍法,制备了一批不同钾含量的K_xMoP/Al₂O₃(x表示K与Mo摩尔比,0≤x≤3)催化剂,考察其对高硫合成气制甲硫醇性能的影响,并采用X射线衍射分析(XRD)、程序升温还原法(TPR)和激光拉曼光谱(LRS)等技术手段对催化剂进行了表征。结果表明,氧化铝负载的磷钼氧化物前驱体在850 ℃经H₂气还原制备出了MoP/Al₂O₃催化剂,少量添加钾催化剂有较高的甲烷选择性,大量添加钾助剂促进了催化剂表面活泼钼硫物种的生成,使得磷化钼基催化剂有较好的甲硫醇选择性,而过量添加钾又会阻碍了甲硫醇的生成。当n(K)/n(Mo)比在2~2.5之间时,磷化钼基催化剂对该反应有较好的催化活性。

关键词: 钾助剂, 磷化钼, 高硫合成气, 甲硫醇

Abstract:

A series of K_xMoP/Al₂O₃(x is K/Mo molar ratio, 0≤x≤3) catalysts with different K/Mo molar ratios was prepared through co-impregnation and characterized using X-ray diffraction(XRD), temperature-programmed reduction(TPR) and laser Raman spectroscopy(LRS). The effects of different potassium content of the catalysts for the synthesis of methyl mercaptan from high H₂S-containing syngas were investigated. The results indicate that MoP/Al₂O₃ catalysts are formed by hydrogen reduction at 850 ℃ from phosphorus molybdenum oxide precursor. With a small amount of potassium, the catalysts show higher methane selectivity. Further increase of potassium content promotes the generation of activity molybdenum sulfur phase, showing good methyl mercaptan selectivity. Excessive potassium hinders the generation of methyl mercaptan. When K/Mo molar ratio is between 2 and 2.5, MoP-based catalysts shows good catalytic activity and selectivity.

Key words: potassium, molybdenum phosphide, high H₂S-containing syngas, methyl mercaptan synthesis

周布康, 王琪, 陈亚中, 崔鹏, 沈泽斌, 张庆红, 王野. 钾对高硫合成气制甲硫醇磷钼基催化剂的影响[J]. 应用化学, 2016, 33(9): 1079-1084.

ZHOU Bukang, WANG Qi, CHEN Yazhong, CUI Peng, SHEN Zebin, ZHANG Qinghong, WANG Ye. Effect of Potassium on the Performance of MoP-based Catalysts in Methyl Mercaptan Synthesis from High H₂S-Containing Syngas[J]. Chinese Journal of Applied Chemistry, 2016, 33(9): 1079-1084.

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