A Cobalt Hydride Catalyst for the Hydrogenation of CO2: Pathways for Catalysis and Deactivation

详细信息    查看全文

• 作者：Matthew S. Jeletic ; Monte L. Helm ; Elliott B. Hulley ; Michael T. Mock ; Aaron M. Appel ; John C. Linehan
• 刊名：ACS Catalysis
• 出版年：2014
• 出版时间：October 3, 2014
• 年：2014
• 卷：4
• 期：10
• 页码：3755-3762
• 全文大小：332K
• ISSN：2155-5435

文摘

The complex Co(dmpe)b>2b>H catalyzes the hydrogenation of COb>2b> at 1 atm and 21 掳C with significant improvement in turnover frequency relative to previously reported second- and third-row transition-metal complexes. New studies are presented to elucidate the catalytic mechanism as well as pathways for catalyst deactivation. The catalytic rate was optimized through the choice of the base to match the pKb>ab> of the [Co(dmpe)b>2b>(H)b>2b>]⁺ intermediate. With a strong enough base, the catalytic rate has a zeroth-order dependence on the base concentration and the pressure of hydrogen and a first-order dependence on the pressure of COb>2b>. However, for COb>2b>:Hb>2b> ratios greater than 1, the catalytically inactive species [(渭-dmpe)(Co(dmpe)b>2b>)b>2b>]²⁺ and [Co(dmpe)b>2b>CO]⁺ were observed.<br>

Keywords:

COb>2b>; cobalt; hydrogenation; catalysis; high-pressure NMR