Unprecedentedly high formic acid dehydrogenation activity on an iridium complex with an N,N'-diimine ligand in water.
Unprecedentedly high formic acid dehydrogenation activity on an iridium complex with an N,N'-diimine ligand in water.
复制标题
DOI：
10.1002/chem.201502086
复制
发表时间：
2015-09
期刊：
影响因子：
--
通讯作者：
Zhijun Wang;Sheng-mei Lu;Jun Li;Jijie Wang;Can Li
中科院分区：
文献类型：
--
作者：
Zhijun Wang;Sheng-mei Lu;Jun Li;Jijie Wang;Can Li
甲酸(FA)脱氢制氢具有广阔的应用前景。目前的大多数FA脱氢催化剂只有在碱或添加剂存在的情况下才有效。本文报道了新开发的含共轭N，N‘-二亚胺配体的Ir络合物在不添加碱或添加剂的情况下用于水中FA的脱氢。以[IrCp*Cl2]2和2，2‘-二-1，4，5，6-四氢嘧啶(L2)为催化剂，在90℃时，[Cp*Ir(L1)Cl]Cl(L1=2，2’-bi-2-imidazoline)催化体系的转化率(TOF)为487 500 h(-1)，转化率(TON)为2 400 000，是迄今报道的FA脱氢反应的最高转化率。一项机理研究表明，[Ir-H]中间物种的形成是催化循环中的速率决定步骤。
Hydrogen production from the dehydrogenation of formic acid (FA) is promising. Most of the current catalysts for FA dehydrogenation are effective only in the presence of bases or additives. We report here newly developed iridium complexes containing conjugated N,N'-diimine ligands for FA dehydrogenation in water without the addition of bases or additives. A turnover frequency (TOF) of 487 500 h(-1) with [Cp*Ir(L1)Cl]Cl (L1=2,2'-bi-2-imidazoline) at 90 °C and a turnover number (TON) of 2 400 000 with in situ prepared catalyst from [IrCp*Cl2 ]2 and 2,2'-bi-1,4,5,6-tetrahydropyrimidine (L2) at 80 °C were obtained, the highest values reported for FA dehydrogenation to date. A mechanistic study reveals that the formation of [Ir-H] intermediate species is the rate-determining step in the catalytic cycle.