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Mechanism of the Catalytic Reduction of CO and CO_2 at Ordinary Temperature and in Atmospheric Pressure

常温常压催化还原CO和CO_2机理

基本信息

批准号：
62550592
负责人：
OGURA Kotaro
金额：
$ 1.15万
依托单位：
Yamaguchi University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1988
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-62550592/
关键词：
carbon dioxide carbon monoxide electrode mediator homogeneous catalysis 接触電気化学的還元

项目摘要

Recently, many environmental problems has been pointed out which are caused by the increase of CO_2 in the atmosphere. One of the most serious problems is a rise in temperature due to the buildup of the greenhouse effect. Hence, the study on the reduction of carbon dioxide attracts attention. However, the reduction of CO_2 is very difficult, and it is carried out at elevated temperature and in high pressure.In the present study, CO and CO_2 was catalytically reduced to methanol in the presence of homogeneous catalysis with an electrode mediator, and the reduction mechanism was investigated. The results obtained are as follows:(1) CO and CO_2 were reduced to methanol with high current efficiency.(2) Both IR and ^<13>C-NMR spectra showed the existence of H^<13>COOH, and hence it was suggested that the reduction of CO and CO_2 proceed via meythylformate as an intermediate.(3) The isotope distribution measured by mass analysis showed the formation of CD_3OH and ^<13>CH_3OH.(4) Consequently, the electrocatalytic reduction of CO and CO_2 proceeds by the following scheme: a weak coordination bond is first formed between the central metal and methanol, followed by the insertion of CO_2 (or CO) to form an intermediate metal-ligand-formate complex, and this complex is finally reduced by the electrode mediator with the consumption of protons in solution to methanol and initial metal complex.

近年来，由于大气中CO_2浓度的增加而引起的许多环境问题已被指出。最严重的问题之一是由于温室效应的累积而导致的温度上升。因此，减少二氧化碳的研究引起了人们的关注。本文以CO和CO_2为原料，在均相催化条件下，以电极为介体，对CO和CO_2催化还原为甲醇的反应机理进行了研究。结果表明：（1）CO和CO_2在高电流效率下被还原为甲醇。(2)IR和~ 1C-NMR<13>谱均表明存在H^<13>COOH，推测CO和CO_2的还原反应是通过甲酸甲酯作为中间体进行的。(3)质量分析结果表明，反应产物中有CD_3OH和^ CH_3OH生成<13>。(4)结果表明，CO和CO_2的电催化还原过程是这样进行的：中心金属首先与甲醇形成弱配位键，然后插入CO_2（或CO），形成中间金属-配体-甲酸盐络合物，最后该络合物被电极介体还原，消耗溶液中的质子，生成甲醇和初始金属络合物。