The oxygen reduction reaction (ORR) on a textured silver surface is investigated through computational modeling and experimental measurement. The reaction paths in three possible mechanisms of ORR on pure silver surfaces are analyzed by the transition-state searching method, and the Ag(220) surfaces exhibit an activation energy barrier of the O₂ protonation reaction of 0.504 eV, which is the lowest activation energy barrier among the flat and stepped silver facets. Furthermore, the theoretical calculations show that the ORR overpotential of Ag(220) surfaces is 0.457 V, which is comparable to the overpotential of the Pt(111) catalyst, 0.441 V, indicating that the stepped Ag(220) facet is a high ORR active site on the textured silver surface. The ORR polarization curves of the textured silver surface are measured by the rotating disk electrode method and the experimental ORR activity trend is (220) facet > (111) facet > (200) facet for the textured silver surface. Both experimental and calculation results indicated that the stepped Ag(220) facet is one of high ORR activity origin for pure Ag materials with desirable morphologies. This new insight provides a fundamental understanding of the ORR reaction mechanism of monometallic Ag and the design of advanced catalytic materials based on pure Ag.

中文翻译：

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（220）织构的Ag表面上低电位的碱性溶液中的电化学氧还原反应

通过计算模型和实验测量研究了纹理银表面上的氧还原反应（ORR）。通过过渡态搜索方法分析了纯银表面上ORR的三种可能机理中的反应路径，并且Ag（220）表面表现出O ₂的活化能垒质子化反应为0.504 eV，这是平坦和阶梯状银面中最低的活化能垒。此外，理论计算表明，Ag（220）表面的ORR过电势为0.457 V，与Pt（111）催化剂的过电势0.441 V相当，表明阶梯式Ag（220）面为高ORR质感的银色表面上的活性部位。通过旋转圆盘电极法测量纹理化银表面的ORR极化曲线，并且对于纹理化银表面，实验的ORR活性趋势为（220）切面>（111）切面>（200）切面。实验和计算结果均表明，阶梯式Ag（220）刻面是具有理想形貌的纯Ag材料的高ORR活性来源之一。