催化学报

催化学报 ›› 2006, Vol. 27 ›› Issue (10): 840-842.

• 研究快讯 • 上一篇    下一篇

氧化锆负载氧化钌催化甲醇低温选择氧化合成甲酸甲酯的活性催化剂结构

李为臻,刘海超   

  1. 北京分子科学国家实验室, 分子动态与稳态结构国家重点实验室, 北京大学化学与分子工程学院绿色化学中心, 北京 100871
  • 收稿日期:2006-10-25 出版日期:2006-10-25 发布日期:2010-11-28

Active Structure of Zirconia-Supported Ruthenium Oxide Catalyst for Low-Temperature Oxidation of Methanol to Methyl Formate

LI Weizhen, LIU Haichao*   

  1. Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Green Chemistry Center, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
  • Received:2006-10-25 Online:2006-10-25 Published:2010-11-28

PDF

841

被引次数

8

摘要： 采用ZrO2负载的RuOx催化剂在低温(如373 K)下催化甲醇选择氧化合成甲酸甲酯,发现RuOx的结构可显著影响反应速率和产物选择性. 在相近的甲醇转化率下, RuO2-4物种的催化活性和对甲酸甲酯的选择性明显高于RuO2物种, 表明在ZrO2表面构筑高活性高选择性的RuO2-4结构有利于获得高的甲酸甲酯产率.

关键词: 甲醇, 选择氧化, 甲酸甲酯, 氧化锆, 氧化钌, 负载型催化剂, 结构效应

Abstract: The oxidation of methanol to methyl formate at low temperature (373 K) over the ZrO2-supported RuOx catalyst was studied. The methanol oxidation rate and product selectivity strongly depend on the RuOx structure, which is changed in the Ru surface density range of 0.2[KG-45x]-[KG-20x]3.8 Ru/nm2. The RuOx structure evolves from isolated RuO2-4 species below 0.4 Ru/nm2 to RuO2 clusters above 1.9 Ru/nm2. Such structural evolution with increasing Ru surface density leads to a decrease in the methanol oxidation rate on per Ru atom and on per exposed Ru atom (i.e. turnover rate). This reveals that RuO2-4 species are more reactive than RuO2 species, which is consistent with the higher reducibility of the RuO2-4 structure. These RuO2-4 species are also more selective than the RuO2 species for the methyl formate formation at similar methanol conversion; a ～96% methyl formate selectivity (at ～15% methanol conversion) was attained at 0.2 Ru/nm2 with predominant RuO2-4 structure. These findings suggest that the highly active and selective RuO2-4 structure is required for achieving high methyl formate productivity.

Key words: methanol, selective oxidation, methyl formate, zirconia, ruthenium oxide, supported catalyst, structural effect