Core-Shell-Like Structured Co3O4@SiO2 Catalyst for Highly Efficient Catalytic Elimination of Ozone.

Co3O4 is an environmental catalyst that can effectively decompose ozone, but is strongly affected by water vapor. In this study, Co3O4@SiO2 catalysts with a core-shell-like structure were synthesized following the hydrothermal method. At 60% relative humidity and a space velocity of 720,000 h-1, the prepared Co3O4@SiO2 obtained 95% ozone decomposition for 40 ppm ozone after 6 h, which far outperformed that of the 25wt% Co3O4/SiO2 catalysts. The superiority of Co3O4@SiO2 is ascribed to its core@shell structure, in which Co3O4 is wrapped inside the SiO2 shell structure to avoid air exposure. This research provides important guidance for the high humidity resistance of catalysts for ozone decomposition.

Highly selective conversion of CO2 to methanol on the CuZnO-ZrO2 solid solution with the assistance of plasma.

CuZnO-ZrO2-C was prepared by a co-precipitation method. For comparison, CuZnO-ZrO2-PC and CuZnO-ZrO2-CP were prepared by glow discharge plasma. The catalysts were characterized via the XRD, N2 adsorption-desorption, TEM, SEM, EDS, XPS, CO2-TPD and H2-TPR techniques. The catalysts were comparatively investigated for CO2 conversion and methanol selectivity in a fixed-bed reactor under the condition of 2 MPa, 250 °C, H2/CO2 = 3/1 and GHSV = 12 000 mL g-1 h-1. The results showed that the activities of the catalysts increased in the order of CuZnO-ZrO2-PC > CuZnO-ZrO2-CP > CuZnO-ZrO2-C. Moreover, the CO2 conversion of CuZnO-ZrO2-C increased by 38.9% via treatment with glow discharge plasma. The results are well explained based on the CO2-TPD and H2-TPR characterizations of the catalysts.