催化学报

催化学报 ›› 2009, Vol. 30 ›› Issue (12): 1281-1286.

• 研究论文 • 上一篇    下一篇

贵金属对 NM/WO3-ZrO2 (NM = Ru, Rh 和 Pd) 催化乙烯直接氧化制乙酸反应的影响

王丽霞 1,2, 徐庶亮 1,2, 楚文玲 1, 杨维慎 1   

  1. 1 中国科学院大连化学物理研究所催化基础国家重点实验室, 辽宁大连 116023 2 中国科学院研究生院, 北京 100049
  • 收稿日期:2009-12-25 出版日期:2009-12-25 发布日期:2013-09-29

Influence of Noble Metals on the Direct Oxidation of Ethylene to Acetic Acid over NM/WO3-ZrO2 (NM = Ru, Rh, and Pd) Catalysts

WANG Lixia1,2, XU Shuliang1,2, CHU Wenling1,#, YANG Weishen1,*   

  1. 1State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China 2Graduate University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2009-12-25 Online:2009-12-25 Published:2013-09-29

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摘要： 研究了负载 Ru, Rh 和 Pd 的 WO3-ZrO2 催化剂在乙烯直接氧化制乙酸反应中的催化性能. 结果显示, 负载的贵金属对催化剂的催化性能有非常重要的影响. Rh/WO3-ZrO2 催化剂具有最高的乙烯转化率, 而 Ru/WO3-ZrO2 催化剂对反应几乎没有活性. H2 化学吸附结果显示, 高的催化性能来源于高的金属分散度. Pd/WO3-ZrO2 催化剂显示了最高的乙酸选择性 (75%), 而其它两个催化剂的乙酸选择性都非常低 (~10%). 程序升温氧化和程序升温还原结果显示, 贵金属–O 键的键强对产物的选择性具有重要的影响. 弱的贵金属–O 键可以通过将氧插入到乙烯和/或乙醛中而有利于乙酸的生成, 而强的贵金属–O 键会导致乙烯完全氧化为 COx.

关键词: 乙烯, 氧化, 乙酸, 氧化钨, 氧化锆, 钯, 钌, 铑

Abstract: Ru-, Rh-, and Pd/WO3-ZrO2 catalysts were studied for the direct oxidation of ethylene to acetic acid. The catalytic activity and selectivity depended strongly on the noble metals used. Rh/WO3-ZrO2 gave the highest conversion of ethylene, whereas Ru/WO3-ZrO2 was almost inactive. The higher catalytic activity was attributed to a better metal dispersion. Pd/WO3-ZrO2 gave the highest selectivity for acetic acid (75%), with the selectivity of the other two catalysts being rather low (~10%). Temperature-programmed oxidation and H2 reduction experiments were used to show that the strength of the noble metal–oxygen bond played an important role in product distribution. A weak metal–oxygen bond favored the formation of acetic acid, while a strong metal–oxygen bond favored the combustion of ethylene to COx.

Key words: ethylene, oxidation, acetic acid, tungstated zirconia, palladium, ruthenium, rhodium