Strong Metal–Support Interaction of Ru on TiO₂ Derived from the Co-Reduction Mechanism of Ru_xTi_1–xO₂ Interphase

Strong metal–support interactions (SMSIs) play a crucial role in the catalytic performance of supported metal catalysts. Researchers hypothesize that there is a migration of the support over preexisting metal nanoparticles during pretreatment. In the present work, a distinct mechanism of generating an SMSI by the co-reduction of the oxide interphase is evaluated over Ru/TiO₂ catalysts. Formation of the Ru_xTi_1–xO₂ oxide interphase is augmented in a facile manner by increasing the calcination temperature over the Ru/TiO₂ catalysts, whereas increasing the encapsulation of the TiO_x overlayer on metallic Ru nanoparticles occurs in the subsequent reduction of this oxide interphase. In contrast, the SMSI generated by the conventional mechanism is highly suppressed over the RuO₂/TiO₂ phase calcined at low temperatures. Because of this improved SMSI on a Ru/TiO₂ catalyst, the catalyst exhibits an enhanced activity in CO₂ methanation with 100% CH₄ selectivity. The findings suggest a means of facilitating SMSI generation by the co-reduction mechanism and offer an alternative pathway to modulating the catalytic properties of supported metal catalysts.