Yin Hongxia, Xiao Hengbo, Qin Ruimin, Chen Jin, Tan Fa, Zhang Wu, Zhao Jian, Zeng Liqing, Hu Yufeng, Pan Fei, Lei Pengxiang, Yuan Songliu, Qian Lihua, Su Yaqiong, Zhang Zhen
School of Physics, Huazhong University of Science and Technology, Wuhan 430074, P. R. China.
School of Chemistry, Xi'an Key Laboratory of Sustainable Energy Materials Chemistry, State Key Laboratory of Electrical Insulation and Power Equipment, Engineering Research Center of Energy Storage Materials and Devices of Ministry of Education, Xi'an Jiaotong University, Xi'an 710049, P. R. China.
ACS Appl Mater Interfaces. 2023 Apr 26;15(16):20100-20109. doi: 10.1021/acsami.3c00544. Epub 2023 Apr 14.
A heterogeneous interface usually plays a versatile role in modulating catalysis and the durability of hybrid electrocatalysts for oxygen evolution reaction (OER), and its intrinsic mechanism is still in dispute due to an uncertain correlation of initial, intermediate and active phases. In this article, the CoMoO·0.69HO/CoO heterogeneous interface is configured to understand the evolution kinetics of these correlated phases. Due to the chemically and electrochemically "inert" character of CoO support, lattice strain with 3.31% tuning magnitude in primary CoMoO·0.69HO can be inherited after spontaneous dissolution of molybdenum cations in electrolyte, dominating catalytic activity of the reconstructed CoOOH. Raman spectroscopy demonstrates reversible conversion between active CoOOH and amorphous cobalt oxide during OER when positive and negative potentials are sequentially supplied onto hybrid catalysts with favorable strain. Therefore, superior durability with negligible decay after 10 cycles is experimentally identified for intermittent oxygen evolution. Theoretical calculations indicate that appropriate stress within the electrocatalyst could reduce the reaction energy barrier and enhance the OER performance by optimizing the adsorption of intermediates.
异质界面通常在调节用于析氧反应（OER）的混合电催化剂的催化作用和耐久性方面发挥多种作用，由于初始、中间和活性相之间的相关性不确定，其内在机制仍存在争议。在本文中，构建了CoMoO·0.69HO/CoO异质界面以了解这些相关相的演化动力学。由于CoO载体具有化学和电化学“惰性”特性，在钼阳离子在电解质中自发溶解后，初生CoMoO·0.69HO中具有3.31%调谐幅度的晶格应变可以被继承，主导了重构CoOOH的催化活性。拉曼光谱表明，当向具有良好应变的混合催化剂依次施加正电位和负电位时，在OER过程中活性CoOOH和非晶态氧化钴之间存在可逆转换。因此，通过实验确定了间歇性析氧具有优异的耐久性，在10次循环后衰减可忽略不计。理论计算表明，电催化剂内的适当应力可以降低反应能垒，并通过优化中间体的吸附来提高OER性能。
