Sinha Soumalya, Sonea Ana, Shen William, Hanson Samuel S, Warren Jeffrey J
Department of Chemistry , Simon Fraser University (SFU) , 8888 University Drive , Burnaby , British Columbia V5A 1S6 , Canada.
Inorg Chem. 2019 Aug 19;58(16):10454-10461. doi: 10.1021/acs.inorgchem.9b01060. Epub 2019 Jul 25.
The development of molecular catalysts and materials that can convert carbon dioxide (CO) into a value-added product is a great chemical challenge. Molecular catalysts set benchmarks in catalyst investigation and design, but their incorporation into solid-state materials, and optimization of the electrochemical operating conditions, is still needed. For example, rhenium(I) diimine catalysts show almost quantitative selectivity for the conversion of CO to carbon monoxide (CO) in acetonitrile (MeCN), but the modification of diimine backbones can be challenging if the goal is to incorporate such molecules into materials. Presented here is a rhenium(I) complex with a 2-(2'-quinolyl)benzimidazole (QuBIm-H) ligand, where N-alkylation with a pyrene derivative allows access to a catalyst that can be adsorbed onto electrodes for aqueous CO reduction chemistry. The rhenium(I) catalysts are inactive for homogeneous CO reduction in MeCN. However, when adsorbed on edge-plane graphite, the same complexes show good activity for heterogeneous aqueous CO reduction, with 90% selectivity for CO. Comparative electrochemical studies between covalent and noncovalent modification of the graphite surfaces were also carried out for related rhenium(I) tricarbonyl complexes.
开发能够将二氧化碳（CO₂）转化为高附加值产品的分子催化剂和材料是一项巨大的化学挑战。分子催化剂在催化剂研究和设计方面树立了标杆，但仍需要将其引入固态材料并优化电化学操作条件。例如，铼（I）二亚胺催化剂在乙腈（MeCN）中对CO₂转化为一氧化碳（CO）显示出几乎定量的选择性，但如果目标是将此类分子引入材料中，二亚胺主链的修饰可能具有挑战性。本文介绍了一种带有2-（2'-喹啉基）苯并咪唑（QuBIm-H）配体的铼（I）配合物，其中与芘衍生物进行N-烷基化可得到一种催化剂，该催化剂可吸附在电极上用于水相CO₂还原化学。铼（I）催化剂在MeCN中对均相CO还原无活性。然而，当吸附在边缘平面石墨上时，相同的配合物对非均相水相CO还原显示出良好的活性，对CO的选择性为90%。还对相关铼（I）三羰基配合物进行了石墨表面共价和非共价修饰之间的比较电化学研究。
