A Hydrothermally Stable Irreducible Oxide-Modified Pd/MgAl2 O4 Catalyst for Methane Combustion.

Catalytic combustion is promising in removing trace amounts of CH4 to address serious environmental concerns. Supported Pd-based catalysts are most effective but often suffer from low stability in applications owing to the water-vapor-induced sintering. Herein, we develop a universal strategy to prepare irreducible-oxide-modified Pd/MgAl2 O4 catalysts which show high activity and excellent stability against both hydrothemal aging at elevated temperatures and deactivation in long-term reaction under wet conditions. The addition of irreducible oxides inhibited the deep oxidation of Pd in the oxygen-rich conditions, which preserved not only the epitaxial structure but also a suitable active phase of Pd-PdOx on MgAl2 O4 , thus promoting both activity and stability. This work provides new insights into the effect of metal-oxide interaction on CH4 combustion and offers an avenue to design hydrothermally stable and active combustion catalysts for industrial applications.