Exploring an electric-aid ozone decomposition mode to enhance water resistance over manganese oxide monolith catalyst under high humidity

Abstract

In this work, a facile, green, and effective reaction mode of electric-aid ozone decomposition (EAOD) was developed over a manganese-based monolith catalyst for eliminating ozone under high humidity. The catalyst was prepared by directly growing α-MnO2 nanorods on Al honeycomb substrate (MnO2/Al) via a simple hydrothermal process, and the EAOD mode was performed just by connecting the MnO2/Al monolith catalyst with a DC power supply during ozone decomposition reaction. In the EAOD mode reaction, the MnO2/Al catalyst exhibited a stable ozone conversion efficiency of over 82 % and excellent stability over 720 min under a relative humidity of 90%, well beyond the performance of catalyst in the conventional ozone decomposition reaction without the help of electric aid. Here, the water evaporation by the external electric field generated from the EAOD mode hinders the competitive adsorption of water vapor on the active sites of MnO2/Al catalyst, consequently enhances its water resistance. Moreover, increasing input electric current of the DC power supply could further improve the catalytic activity and stability of the monolith catalyst for ozone decomposition in EAOD mode reaction.