Facet-Defined Strain-Free Spinel Oxide for Oxygen Reduction

• DOI: 10.1021/acs.nanolett.2c00238
• Publication Date: 2022-03-31T14:39:32Z
• Authors: Jinwoung Jo; Ji Mun Yoo; Dong Hyeon Mok; Ho Yeon Jang; Jiheon Kim; Wonjae Ko; Kyungbeen Yeom; Megalamane S. Boo...; Seoin Back; Yung-Eun Sung; Taeghwan Hyeon
• Keywords: Facet (psychology); Strain (injury); Chronoamperometry

Exposing facet and surface strain are critical factors affecting catalytic performance but unraveling the composition-dependent activity on specific facets under strain-controlled environment is still challenging due to synthetic difficulties. Herein, we achieved a (001) facet-defined Co-Mn spinel oxide with different compositions using epitaxial growth Co3O4 nanocube template. We adopted composition gradient synthesis relieve layer by layer, minimizing effect activity. In this system, experimental calculational analyses of model oxygen reduction reaction (ORR) reveals volcano-like trend Mn/Co ratios because an adequate charge transfer from octahedral-Mn neighboring Co. Co0.5Mn0.5 as optimized ratio exhibits both outstanding ORR (0.894 V vs RHE in 1 M KOH) stability (2% loss against chronoamperometry). By controlling strain, study provides well-defined platform for investigating composition-structure-activity relationships electrocatalytic processes.