Strong Metal–Support Interaction of Ru on TiO ₂ Derived from the Co-Reduction Mechanism of Ru _<i>x</i> Ti _{1– <i>x</i>} O ₂ Interphase

Abstract

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 RuxTi1–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 TiOx 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.