Electrochemical Reduction of Carbon Dioxide to Formate on Tin–Lead Alloys

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• 作者：Song Yi Choi ; Soon Kwan Jeong ; Hak Joo Kim ; Il-Hyun Baek ; Ki Tae Park
• 刊名：ACS Sustainable Chemistry & Engineering
• 出版年：2016
• 出版时间：March 7, 2016
• 年：2016
• 卷：4
• 期：3
• 页码：1311-1318
• 全文大小：512K
• ISSN：2168-0485

文摘

Electrochemical reduction of carbon dioxide (CO₂) to formate (HCOO^–) in aqueous solution is studied using tin–lead (Sn–Pb) alloys as new electrocatalysts. In electrochemical impedance spectroscopy (EIS) measurements, lower charge-transfer resistance is observed for the alloy electrodes when compared to the single metal electrodes such as Sn and Pb. The results of X-ray photoelectron spectroscopy (XPS) and cyclic voltammetric (CV) analysis show that the Sn in the Sn–Pb alloys facilitates the formation of oxidized tin (SnO_x) and metallic lead (Pb⁰) on the alloy surface by inhibiting the formation of low-conductive lead oxide (PbO) film. The CV analysis confirms that the Sn–Pb alloys exhibit higher reduction current than the single metal electrodes under CO₂ atmosphere. The Faradaic efficiency (FE) and the partial current density (PCD) of HCOO^– production on the alloy electrodes is investigated by electroreduction experiments at −2.0 V (vs Ag/AgCl) in an H-type cell. As results, respectively more than 16% and 25% higher FE and PCD of HCOO^– are obtained from the Sn–Pb alloys compared to the single metal electrodes. A Sn–Pb alloy including surface composition of Sn_56.3Pb_43.7 exhibits the highest FE of 79.8% with the highest PCD of 45.7 mA cm^–2.