Li Ruchun, Hu Bihua, Yu Tongwen, Chen Haixin, Wang Yi, Song Shuqin
The Key Lab of Low-carbon Chemistry and Energy Conservation of Guangdong Province School of Materials Science and Engineering School of Chemical Engineering and Technology Sun Yat-sen University Guangzhou 510275 China.
Adv Sci (Weinh). 2020 Jan 21;7(5):1902830. doi: 10.1002/advs.201902830. eCollection 2020 Mar.
Rational design of unique pre-catalysts for highly active catalysts toward catalyzing the oxygen evolution reaction (OER) is a great challenge. Herein, a Co-derived pre-catalyst that allows gradual exposure of CoOOH that acts as the active center for OER catalysis is obtained by both phosphate ion surface functionalization and Mo inner doping. The obtained catalyst reveals an excellent OER activity with a low overpotential of 265 mV at a current density of 10 mA cm and good durability in alkaline electrolyte, which is comparable to the majority of Co-based OER catalysts. Specifically, the surface functionalization produces lots of Co-PO species with oxygen vacancies which can trigger the surface self-reconstruction of pre-catalyst for a favorable OER reaction. Density functional theory calculations reveal that the Mo doping optimizes adsorption-free energy of *OOH formation and thus accelerates intrinsic electrocatalytic activity. Expanding on these explorations, a series of transition metal oxide pre-catalysts are obtained using this general design strategy. The work offers a fundamental understanding toward the correlation among surface-structure-activity for the pre-catalyst design.
合理设计用于催化析氧反应（OER）的高活性催化剂的独特前体催化剂是一项巨大挑战。在此，通过磷酸根离子表面功能化和钼内部掺杂获得了一种钴衍生的前体催化剂，该催化剂能使作为OER催化活性中心的CoOOH逐渐暴露。所获得的催化剂在10 mA cm的电流密度下具有265 mV的低过电位，展现出优异的OER活性，并且在碱性电解质中具有良好的耐久性，这与大多数钴基OER催化剂相当。具体而言，表面功能化产生了大量具有氧空位的Co-PO物种，这些物种可引发前体催化剂的表面自重构以利于OER反应。密度泛函理论计算表明，钼掺杂优化了*OOH形成的吸附自由能，从而加速了本征电催化活性。基于这些探索，使用这种通用设计策略获得了一系列过渡金属氧化物前体催化剂。这项工作为前体催化剂设计中的表面-结构-活性相关性提供了基本认识。
