Polymer Nanofilm-Coated Co-Mn Oxide Nanoparticle Catalysts for Transmembrane CO Oxidation at 50 °C under Moisture-Rich Conditions

Coating with polymer nanofilm can dramatically improve not only the structural stability of nanostructured transition metal oxides but also their catalytic performance under moisture-rich conditions at low temperature. In this work, upon optimization of the polymer nanofilm-coated nanoparticle catalysts MnaCobOx we have achieved an efficient and relatively stable CO oxidation at 50 degrees C under moisture-rich condition (0.6 vol % H2O). The catalysts were characterized by several complementary techniques (TEM, TG, FTIR, XPS, XRD, TPD, etc.), among which X-ray photoelectron spectroscopy (XPS) showed that the catalytic activities were highly correlated to the ratios of Co3+/Co2+ and Mn2+/Mn3+ as well as the percentage of vacancy oxygen (O-v), indicating that, in addition to the water-repulsing effect of the coating polymer, the synergistic actions among the Co-Mn ion pairs and oxygen vacancies (V-O) played important roles for the low-temperature transmembrane CO oxidation. The mechanism for CO catalytic oxidation inside the polymer nanofilm coating has been discussed.