Phase engineering of black TiO2 supported Ru for hydrogen electrocatalysis

For supported metal catalysts, phase engineering emerges as an effective route to elevate electrocatalytic efficacy. However, conventional phase regulation strategies based on thermal reduction often suffer from prolonged synthesis processes and tend to induce metal aggregation, which ultimately limits the exposure of active sites. Herein, an ultrafast microwave quasi-solid approach (90 s) is adopted to synthesize Ru nanoclusters embedded into black anatase TiO 2 lattice (Ru/TiO 2 -A) with abundant oxygen vacancy, and surface decorated Ru nanoparticles onto black rutile TiO 2 . Engineered lattice-embedded configurations and co-generated oxygen vacancies collectively dictate catalytic performance and structural durability. As an electrocatalyst for hydrogen-related reactions (HER/HOR), Ru/TiO 2 -A featuring Ru nanoclusters exhibits superior performance to Ru nanoclusters on black rutile TiO 2 (Ru/ TiO 2 -R) in alkaline electrolyte, demonstrating a lower overpotential (44 mV vs. 90 mV @ 10 mA cm⁻²) and higher mass activity (20.99 A mg -1 Ru vs. 6.71 Amg -1 Ru @ 100 mV). Support phase engineering enhances water dissociation kinetics and modulates adsorption-desorption equilibria of reactive intermediates. This work is expected to advance the catalytic systems and provide novel approach to rational prepare efficient electrocatalysts toward hydrogen electrode reactions. SYNOPSIS TOC Ru/TiO 2 -A exhibits excellent HER and HOR performance and high mass activity in 1 M KOH. The embedded structure of Ru into black anatase TiO 2 lattice triggers more electron transfer and optimize the adsorption/desorption energies of multi-intermediates and decreased the energy barrier for H 2 O dissociation to boost the electrocatalytic performance. If you are submitting your paper to a journal that requires a synopsis, see the journal’s Instructions for Authors for details. • The phase of the support can tune the metal-support interactions to obtain various geometric structure of the noble metals. • Herein, the embedded structure in the anatase TiO 2 structure exhibits stronger electronic structure relative to the surface supported nanostructure. • An ultrafast microwave quasi-solid approach (90 s) is adopted to synthesize Ru nanoclusters embedded into black anatase TiO 2 lattice (Ru/TiO 2 -A) with abundant oxygen vacancy, and surface decorated Ru nanoparticles onto black rutile TiO 2 . • Ru/TiO 2 -A featuring Ru nanoclusters exhibits superior performance to Ru nanoclusters on black rutile TiO 2 (Ru/ TiO 2 -R) in alkaline electrolyte, demonstrating a lower overpotential and higher mass activity.