Self‐Assembled Pd@CeO₂/γ‐Al₂O₃ Catalysts with Enhanced Activity for Catalytic Methane Combustion

Abstract

Pd@CeO 2 /Al 2 O 3 catalysts are of great importance for real applications, such as three‐way catalysis, CO oxidation, and methane combustion. In this article, the Pd@CeO 2 core@shell nanospheres are prepared via the autoredox reaction in aqueous phase. Three kinds of methods are then employed, that is, electrostatic interaction, supramolecular self‐assembly, and physical mixing, to support the as‐prepared Pd@CeO 2 nanospheres on γ‐Al 2 O 3 . A model reaction of catalytic methane‐combustion is employed here to evaluate the three Pd@CeO 2 /γ‐Al 2 O 3 samples. As a result, the sample Pd@CeO 2 ‐S‐850 prepared via supramolecular self‐assembly and calcined at 850 °C exhibits superior catalytic performance to the others, which has a far lower light‐off temperature ( T 50 of about 364 °C). Moreover, almost no deterioration of Pd@CeO 2 ‐S‐850 is observed after five sequent catalytic cycles. The analysis of H 2 ‐TPR curves concludes that there exists hydrogen spillover related to the strong metal–support interaction between Pd species and oxides. The strong metal–support interaction and the specific surface areas might be responsible for the catalytic performance of the Pd@CeO 2 samples toward catalytic methane combustion.