In Situ Synthesis of Monolithic Cu<sub>2</sub>O–CuO/Cu Catalysts for Effective Ozone Decomposition
Anqi Wang, Jian Guan, Le Zhang, Hang Wang, Guojun Ma, Guijun Fan, Wenxiang Tang, Ning Han, Yunfa Chen
Abstract
Nowadays, ozone (O3) has become a worldwide pollutant, and it is challenging to prepare monolithic O3 decomposition catalysts substituting the conventional complicated process of adhering catalyst powders onto porous substrates. Herein, monolithic Cu2O–CuO/Cu catalysts are obtained facilely by in situ thermal oxidizing–reducing copper foam. After optimization, the CuO nanowires (NWs) are first produced by annealing Cu foam in O2 at 400 °C for 2 h and then the NW surface is reduced into Cu2O by annealing in Ar/H2 at 350 °C for 2 h. The obtained Cu2O–CuO/Cu monolithic catalyst exhibits high catalytic activity to 20 ppm O3, maintaining 100% at a space velocity of 11,000 h–1 and even about 94% at 38,000 h–1. The catalytic ability toward O3 can be attributed to the generated Cu+/Cu2+ redox couples, the donor/acceptor-type point defects, and the Cu2O–CuO p–p heterojunction. This demonstrates the successful and convenient preparation of the monolithic catalyst for rapid, controllable, and productive O3 removal applications.