Iodide Oxidation Reaction Catalyzed by Ruthenium–Tin Surface Alloy Oxide for Efficient Production of Hydrogen and Iodine Simultaneously

• Published in: ACS sustainable chemistry & engineering Vol. 9; no. 26; pp. 8803 - 8812
• Main Authors: Adam, Dessalew Berihun, Tsai, Meng-Che, Awoke, Yohannes Ayele, Huang, Wei-Hsiang, Yang, Yaw-Wen, Pao, Chih-Wen, Su, Wei-Nien, Hwang, Bing Joe
• Format: Journal Article
• Language: English
• Published: American Chemical Society 05.07.2021
• Subjects: iodide oxidation reaction; Faradaic efficiency; oxygen evolution reaction; hydrogen production
• ISSN: 2168-0485; 2168-0485
• DOI: 10.1021/acssuschemeng.1c01867

A new type of electrolysis by employing iodide oxidation reaction (IOR) via a ruthenium–tin surface alloy oxide (RuSn SAO) catalyst was designed to replace oxygen evolution reaction (OER) for efficient production of hydrogen, which not only enhances energy conversion efficiency but also produces a high-value commodity chemical, iodine, rather than O2, in the anodic cell. Remarkably, the excellent activity of RuSn SAO enables it to be the best catalyst for IOR toward energy-saving hydrogen production. Its two-electrode acidic electrolyzer requires a cell voltage of only 1.07 V to afford 10 mA cm–2, which is 0.51 V less than that required for OER to reach the same current density. Thus, the system drastically reduces energy consumption by more than 40% compared to pure water electrolysis. The chronopotentiometric test shows that the RuSn SAO needed a super-low overpotential increase of Δη = 70 mV at 10 mA cm–2 together with recorded highly durable stability in the acidic electrolyte, indicating enhanced catalytic activity. Furthermore, this strategy simultaneously produces hydrogen with ∼100% Faradic efficiency and a high-value commodity chemical, I2, making H2 production potentially costless. Thus, the proposed concept paves a new way to facilitate the realization of hydrogen economics.