Strong metal-support interaction assisted redispersion strategy for obtaining ultrafine and stable IrO2/Ir active sites with exceptional methane oxidation activity

Skillful arrangement of the active sites with stable dispersion and desired chemical states on the support surface is vital for their powerful application in catalysis, but remains a daunting challenge. Herein, we present a unique redispersion strategy for well dispersing and stabilizing IrO 2 /Ir active sites over TiO 2 as an advanced catalyst for low temperature CH 4 oxidation. The as-designed Ir/TiO 2 with a 1 wt.% Ir loading amount exhibits a (>)99 % CH 4 conversion and excellent durability at a temperature as low as 320 °C, which ranges among the best of state-of-the-art methane combustion catalysts. Various characterizations and DFT calculations were performed to reveal the redispersion mechanism and understand the reason for the enhanced performance. The superior performance is related to the proper chemical state of complex IrO 2 /Ir active sites and their ultrafine and stable dispersion, all relating to the strong metal-support interaction (SMSI) induced redispersion process. Such SMSI assisted active sites redispersion strategy provides useful guidance for the rational design of efficient Ir-based and other noble metal catalysts.