Hydrogen peroxide production from oxygen and formic acid by homogeneous Ir-Ni catalyst
Hydrogen peroxide production from oxygen and formic acid by homogeneous Ir-Ni catalyst
复制标题
均相 Ir-Ni 催化剂由氧气和甲酸生产过氧化氢
DOI：
10.1039/d1dt01431e
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发表时间：
2021
影响因子：
4
通讯作者：
Hong Dachao
中科院分区：
文献类型：
--
作者：
Shimoyama Yoshihiro;Ohgomori Yuji;Kon Yoshihiro;Hong Dachao
以邻位异双核Ir-Ni配合物为催化剂，氧气和甲酸在室温下直接反应生成过氧化氢。来自异双核Ir和Ni中心的协同催化被证明通过比较其活性的单核Ir和Ni配合物的组分。通过UV-vis、ESI-TOF-MS和1H NMR谱检测到反应中间体Ir-Al 2 O3。据透露，Ir部分作为一个活性物种的Ir-过氧化氢，与氧气反应，以提供一个Ir-过氧化氢物种通过O2插入，这是速率决定步骤H2 O2生产。同时，Ni部分通过活化作为质子源的溶剂促进H2 O2的形成。我们还发现，H2 O2的生产是强烈的影响，溶剂介电常数（DE），最高的H2 O2浓度得到在乙二醇中具有中等DE。通过动力学分析、同位素标记实验和密度泛函理论计算，讨论了Ir-Ni配合物催化H2 O2生成的机理。
Hydrogen peroxide was directly produced from oxygen and formic acid, catalysed by a hetero-dinuclear Ir–Ni complex with two adjacent sites, at ambient temperature. Synergistic catalysis derived from the hetero-dinuclear Ir and Ni centres was demonstrated by comparing its activity to those of the component mononuclear Ir and Ni complexes. A reaction intermediate of Ir-hydrido was detected by UV-vis, ESI-TOF-MS, and 1H NMR spectroscopies. It was revealed that the Ir moiety serves as an active species of Ir-hydrido, reacting with oxygen to afford an Ir-hydroperoxide species through O2 insertion, which is the rate-determining step for H2O2 production. Meanwhile, the Ni moiety promotes H2O2 formation by activating solvents as proton sources. We also found that H2O2 production is strongly affected by the solvent dielectric constants (DE); the highest H2O2 concentration was obtained in ethylene glycol with a moderate DE. The catalytic mechanism of H2O2 production by the Ir–Ni complex was discussed, based on kinetic analysis, isotope labelling experiments, and theoretical DFT calculations.