CO_2电催化还原的研究——Ⅳ.光透薄层电极(OTTLE)研究反应机理

Studies on the Electrocatalytic Reduction of Carbon Dioalde——IV. Studies on the Mechanism of the Electrocatalytic Reduction Reaction by Optically Thansparent Thin layer Electrode (OTTLE)

本文用薄层电极的光谱电化学技术,确定了催化剂碘化四[4-(三甲铵基)苯基]卟啉合钴(CoTMAPI)当恒电位控制在0.6、-0.3、-1.0V时分别得到一价、二价、三价中心离子的可见紫外光谱;检测到在咪唑存在下,CO_2与一价钴卟啉生成的配合物。并用易于与一价钴卟啉配位的碘甲烷来进一步证实,从而肯定了CO_2的电催化还原是通过形成CO_2配合物中间体的反应途径。

In this paper, a new OTTLE spectroelectrochemistry technique was used to investigate the mechanism of tetrakis (4-trimethylanilino) porphine iodide (CoTMAPI) on the electrocatalytic reduction of CO_2. When constant voltage was controlled to 0.6, -0.3 and -1.0V the UV spectra of the monovalent, divalent and trivalent ions were obtained, respectively. In the presence of imidazole, the controlled-potential(-1.0V) electrolysis was performed in a solution of CoTMAPI (saturated with CO_2). The UV- spectrum of intermediate [CO_2·Co(I)ImTMAPI] was detected with absorption peaks at 434.0, 603.6nm and a catalytic cycle for the electrocatalytic reduction of CO_2 was suggested.