Interfacial compatibility critically controls Ru/TiO 2 metal-support interaction modes in CO 2 hydrogenation.

Supports can widely affect or even dominate the catalytic activity, selectivity, and stability of metal nanoparticles through various metal-support interactions (MSIs). However, underlying principles have not been fully understood yet, because MSIs are influenced by the composition, size, and facet of both metals and supports. Using Ru/TiO 2 supported on rutile and anatase as model catalysts, we demonstrate that metal-support interfacial compatibility can critically control MSI modes and catalytic performances in CO 2 hydrogenation. Annealing Ru/rutile-TiO 2 in air can enhance CO 2 conversion to methane resulting from enhanced interfacial coupling driven by matched lattices of RuO x with rutile-TiO 2 ; annealing Ru/anatase-TiO 2 in air decreases CO 2 conversion and converts the product into CO owing to strong metal-support interaction (SMSI). Although rutile and anatase share the same chemical composition, we show that interfacial compatibility can basically modify metal-support coupling strength, catalyst morphology, surface atomic configuration, MSI mode, and catalytic performances of Ru/TiO 2 in heterogeneous catalysis.