Rational design of three-dimensional porous Ir-supported TiO2–ZrO2 microspheres for low temperature methane combustion

Abstract

Construction of efficient and stable catalytic combustion materials for the removal of unburnt methane (CH4) is very critical for both applied environmental catalysis and basic materials research. Herein, a facile hydrothermal approach is designed for the fabrication of Ir/UTZX (Ir/TiO2–ZrO2) catalysts. The as-synthesized Ir/UTZX catalysts possess unique sphere morphology as well as electronic structure, leading to enlarged exposure of catalytic sites and enhancement of redox properties. As a result, the representative Ir/UTZ5 catalyst achieves a CH4 conversion of nearly 100% at 425 °C. Significantly, Ir/UTZ5 displays high long-term stability, with no obvious decrease of catalytic activity in the run of 120 h, which is much higher than those of Ir/TiO2 and Ir/ZrO2 catalysts. Our findings offer insights for designing highly efficient and stable catalysts for CH4 catalytic combustion.