Cordierite-Supported Transition-Metal-Oxide-Based Catalysts for Ozone Decomposition

Abstract

Cordierite-based supported noble-metal-free catalysts for ozone decomposition are elaborated. The cordierite ceramic surface is pretreated with oxalic acid and NaOH, and Mn-Cu-Ni oxide catalysts are prepared by the impregnation method. The mass ratio of the supported oxides in the resulting catalysts is MnO2:CuO:NiO = 3:2:1, and their loadings are from 1.8 to 7.0 wt.%. The pretreated supports and catalysts are characterized by low-temperature N2 adsorption, scanning electron microscopy (SEM), powder X-ray diffraction analysis (XRD), and temperature-programmed reduction with H2 (TPR-H2). The catalysts are tested in ozone decomposition with high airflow rates (20 and 50 L/min) and with initial ozone concentrations of 1 and 2 ppm at temperatures in the range of 25–120 °C. It is shown that a combined treatment of cordierite with oxalic acid and NaOH leads to a developed porous structure and stabilization of supported Mn-Cu-Ni oxides in a highly dispersed state. The high activity of catalysts in ozone decomposition at room temperature and high airflow is demonstrated. The developed catalysts can be recommended for application in purification of air from the ozone because of their high catalytic activity, high mechanical stability, and relatively low weight and cost.