Ambient CO Oxidation on In‐Situ Generated Co3O4 Spinel Surfaces with Random Morphology

Simple surface oxidation of polycrystalline Co‐metal surfaces with molecular oxygen leads to Co3O4 spinel with random morphology. Co2+/Co3+ ratio can be fine‐tuned by oxygen partial pressure and temperature. Predominant Co2+‐containing surfaces was shown to exhibit sustainable ambient CO oxidation activity at ambient temperatures even in the presence of up to 30 ppm moisture content in the reaction feed. Co oxidation by molecular oxygen, random morphology and tolerance towards moisture content up to 30 ppm makes the present effort attractive and also provide further scope to improve the catalytic performance. Our results complement and broaden the ambient CO oxidation catalysis reported for Co3O4 nanorod. Co3O4 with random morphology and tuneable Co3+/Co2+ ratio exhibits sustainable ambient CO oxidation activity even in the presence of 30 ppm moisture. Significant amount of Co2+ present on the surface improves the activity underscores its role in the catalytic activity. Present results complement and broaden the ambient CO oxidation catalysis reported for Co3O4 nanorod in the literature.