Iodide Oxidation Reaction Catalyzed by Ruthenium–Tin Surface Alloy Oxide for Efficient Production of Hydrogen and Iodine Simultaneously
Dessalew Berihun Adam, Meng‐Che Tsai, Yohannes Ayele Awoke, Wei‐Hsiang Huang, Yaw‐Wen Yang, Chih‐Wen Pao, Wei‐Nien Su, Bing−Joe Hwang
Abstract
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.