Strong metal–support interaction of Ru on TiO2 derived from the co-reduction mechanism of RuxTi1−xO2 interphase
Abstract Strong metal–support interaction (SMSI) plays a crucial role in determining the catalytic performances of supported metal catalysts, in which the subsequent migration of supports over the pre-existing metal nanoparticles is generally considered during the pretreatment condition. Herein, a distinct mechanism of SMSI generation by the co-reduction of oxide interphase is addressed over the Ru/TiO2 catalysts. Our results demonstrate that the formation of RuxTi1−xO2 oxide interphase can be facilely augmented by increasing the calcination temperature over Ru/TiO2 catalysts, while a growing encapsulation of TiOx overlayer on metallic Ru nanoparticles can be acquired in the following reduction of this oxide interphase. In contrast, the SMSI generation by the conventional mechanism is highly suppressed over the RuO2/TiO2 phase calcined at a low temperature. Thanks to this improved SMSI on Ru/TiO2 catalyst, it thus possesses an excellent performance in CO2 methanation, with a promoted CO2 conversion activity. Our findings suggest a different mechanism for the SMSI generation through the oxide interphase formation, and it also offers an alternative pathway to tune catalytic properties of supported metal catalysts.
