Therrien Jeffrey A, Wolf Michael O, Patrick Brian O
Department of Chemistry, University of British Columbia , Vancouver, British Columbia V6T 1Z1, Canada.
Inorg Chem. 2014 Dec 15;53(24):12962-72. doi: 10.1021/ic502056w. Epub 2014 Oct 22.
A series of pyridine- and lutidine-linked bis-N-heterocyclic carbene (NHC) palladium pincer complexes were electrochemically characterized and screened for CO2 reduction capability with 2,2,2-trifluoroethanol, acetic acid, or 2,2,2-trifluoroacetic acid (TFA) as proton sources. The lutidine-linked pincer complexes electrocatalytically reduce CO2 to CO at potentials as low as -1.6 V versus Ag/AgNO3 in the presence of TFA. The one-electron reduction of these complexes is shown to be chemically reversible, yielding a monometallic species, with density functional theory studies indicating charge storage on the redox-active ligand, thus addressing a major source of deactivation in earlier triphosphine electrocatalysts.
一系列吡啶和甲基吡啶连接的双-N-杂环卡宾（NHC）钯钳形配合物通过电化学进行了表征，并以2,2,2-三氟乙醇、乙酸或2,2,2-三氟乙酸（TFA）作为质子源，对其二氧化碳还原能力进行了筛选。在TFA存在下，与Ag/AgNO3相比，甲基吡啶连接的钳形配合物在低至-1.6 V的电位下能将二氧化碳电催化还原为一氧化碳。这些配合物的单电子还原显示出化学可逆性，产生一种单金属物种，密度泛函理论研究表明电荷存储在氧化还原活性配体上，从而解决了早期三膦电催化剂失活的一个主要原因。
