Laboratoire d'Electrochimie Moléculaire, Université Paris Cité, CNRS, 75006, Paris, France.
Instituto de Investigaciones Químicas (IIQ), Departamento de Química Inorgánica, Consejo Superior de Investigaciones Científicas (CSIC) and Universidad de Sevilla, Avenida Américo Vespucio 49, 41092, Sevilla, Spain.
Chemistry. 2023 Feb 10;29(9):e202202361. doi: 10.1002/chem.202202361. Epub 2023 Jan 11.
A pyrazole-based ligand substituted with terpyridine groups at the 3 and 5 positions has been synthesized to form the dinuclear cobalt complex 1, that electrocatalytically reduces carbon dioxide (CO ) to carbon monoxide (CO) in the presence of Brønsted acids in DMF. Chemical, electrochemical and UV-vis spectro-electrochemical studies under inert atmosphere indicate pairwise reduction processes of complex 1. Infrared spectro-electrochemical studies under CO and CO atmosphere are consistent with a reduced CO-containing dicobalt complex which results from the electroreduction of CO . In the presence of trifluoroethanol (TFE), electrocatalytic studies revealed single-site mechanism with up to 94 % selectivity towards CO formation when 1.47 M TFE were present, at -1.35 V vs. Saturated Calomel Electrode in DMF (0.39 V overpotential). The low faradaic efficiencies obtained (<50 %) are attributed to the generation of CO-containing species formed during the electrocatalytic process, which inhibit the reduction of CO .
一种基于吡唑的配体，在 3 位和 5 位被三联吡啶基团取代，合成了双核钴配合物 1，该配合物在 DMF 中存在布朗斯台德酸时，电催化还原二氧化碳（CO ）为一氧化碳（CO）。在惰性气氛下进行的化学、电化学和紫外可见光谱电化学研究表明，配合物 1 经历成对的还原过程。在 CO 和 CO 气氛下的红外光谱电化学研究与还原的含 CO 的二钴配合物一致，该配合物是由 CO 的电化学还原产生的。在三氟乙醇（TFE）存在下，电催化研究显示出单活性位机制，当存在 1.47 M TFE 时，在 DMF 中 -1.35 V 对饱和甘汞电极（0.39 V 过电势）时，CO 的选择性高达 94%。获得的法拉第效率低（<50%）归因于在电催化过程中生成的含 CO 物种的生成，这些物种抑制了 CO 的还原。
