Department of Chemistry, Institute of Biomimetic Materials & Chemistry, Anhui Engineering Laboratory of Biomimetic Materials, Division of Nanomaterials & Chemistry, Hefei National Research Center for Physical Sciences at the Microscale, Institute of Energy, Hefei Comprehensive National Science Center, University of Science and Technology of China, Hefei 230026, China.
MOE International Joint Laboratory of Materials Microstructure, Institute for New Energy Materials and Low Carbon Technologies, School of Materials Science & Engineering, Tianjin University of Technology, Tianjin 300384, China.
J Am Chem Soc. 2022 Jul 27;144(29):13163-13173. doi: 10.1021/jacs.2c02989. Epub 2022 Jul 18.
Hydrogen production from water electrolysis in neutral-pH electrolytes can not only avoid the corrosion and safety issues and expand the catalyst option but also potentially integrate with artificial photosynthesis and bioelectrocatalysis. However, heterogeneous catalysts that can efficiently negotiate the sluggish oxygen evolution reaction (OER) in neutral solutions are considerably lacking. Herein, we report a template-assisted strategy for the synthesis of 13 kinds of tube-like nanostructured perovskite oxides (TNPOs) with markedly high Brunauer-Emmett-Teller surface areas. By systematic examination of these TNPOs, we found that the OER activity of TNPOs in neutral solution exhibits a volcano shape as a function of the covalency of transition metal-oxygen bonds. Consequently, our designed Sm-doped LaCoO catalyst yields a geometric current density of 8.5 mA cm at 1.75 V versus the reversible hydrogen electrode in 1 M phosphate buffer solution (pH 7) due to the optimized covalency of Co 3d and O 2p states, representing the most active noble-metal-free OER catalyst in neutral electrolytes reported as yet.
在中性 pH 电解质中进行水的电解制氢不仅可以避免腐蚀和安全问题，扩大催化剂的选择范围，还可以与人工光合作用和生物电化学相集成。然而，能够在中性溶液中高效催化缓慢的析氧反应（OER）的多相催化剂却相当缺乏。在此，我们报告了一种模板辅助策略，用于合成 13 种具有显著高的 Brunauer-Emmett-Teller 比表面积的管状纳米结构钙钛矿氧化物（TNPOs）。通过对这些 TNPOs 的系统研究，我们发现 TNPOs 在中性溶液中的 OER 活性随过渡金属-氧键的共价性呈火山形变化。因此，我们设计的 Sm 掺杂 LaCoO 催化剂在 1 M 磷酸盐缓冲溶液（pH 7）中于 1.75 V 对可逆氢电极的几何电流密度达到 8.5 mA cm，这归因于 Co 3d 和 O 2p 态的优化共价性，代表了迄今为止在中性电解质中报道的最活跃的无贵金属 OER 催化剂。
