Gao Jiajian, Tan Sze Xing, Liu Yan, Liu Bin, Huang Kuo-Wei
Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 1 Pesek Road, Jurong Island, Singapore 627833, Republic of Singapore.
Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong SAR 999077, China.
J Phys Chem Lett. 2023 Jul 20;14(28):6494-6505. doi: 10.1021/acs.jpclett.3c01161. Epub 2023 Jul 13.
Iridium electrocatalysts have been extensively studied for the acidic water oxidation reaction (2HO → O + 4H + 4, also known as the oxygen evolution reaction, OER) in recent years. However, the activity of different iridium catalysts, such as amorphous, crystalline, and metallic ones, varies significantly, and there is no common explanation for the origin of this difference. Here four types of iridium catalysts were selected as models and characterized by various techniques. The redox behavior of iridium catalysts and oxidation of hydrogen peroxide (in the form of OOH) were applied to probe the adsorption energy of oxygen reaction intermediates (*OH, *O, and *OOH) on iridium catalysts under the OER conditions. Structure-activity analysis suggested that the more optimal and broader distribution of adsorption energies on metallic iridium (iridium black) and its good conductivity are the origin of its highest activity among the four different iridium catalysts.
近年来，铱电催化剂已被广泛研究用于酸性水氧化反应（2H₂O → O₂ + 4H⁺ + 4e⁻，也称为析氧反应，OER）。然而，不同的铱催化剂，如非晶态、晶态和金属态的铱催化剂，其活性差异显著，且对于这种差异的起源尚无统一的解释。在此，选择了四种类型的铱催化剂作为模型，并通过各种技术对其进行了表征。利用铱催化剂的氧化还原行为和过氧化氢（以OOH形式）的氧化来探测析氧反应条件下铱催化剂上氧反应中间体（*OH、O和OOH）的吸附能。结构-活性分析表明，金属铱（铱黑）上吸附能分布更优化、更宽泛以及其良好的导电性是其在四种不同铱催化剂中具有最高活性的原因。
