Interfacial compatibility critically controls Ru/TiO2 metal-support interaction modes in CO2 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/TiO2 supported on rutile and anatase as model catalysts, we demonstrate that metal-support interfacial compatibility can critically control MSI modes and catalytic performances in CO2 hydrogenation. Annealing Ru/rutile-TiO2 in air can enhance CO2 conversion to methane resulting from enhanced interfacial coupling driven by matched lattices of RuOx with rutile-TiO2; annealing Ru/anatase-TiO2 in air decreases CO2 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/TiO2 in heterogeneous catalysis.