Spark Ablation Coupled with Powder Aerosolization for the One‐Step Preparation of Ru/TiO ₂ Catalysts for CO ₂ Methanation

Abstract The preparation of powdery heterogeneous catalysts often involves the use of solvents, costly precursors, and thermal treatments in multi‐step processes. Herein, we demonstrate the preparation of Ru nanoparticles on TiO 2 via spark ablation coupled with powder aerosolization, offering a clean and simple route with minimal waste generation and reduced pre‐ and post‐synthesis processing. The as‐prepared Ru/TiO 2 catalyst is readily active in CO 2 methanation reaction, achieving CH 4 formation rate of 0.21 mmolg Ru −1 s −1 and TOF of 0.11 s −1 at 200 °C, outperforming the corresponding formulation prepared by wetness impregnation followed by calcination. The enhanced performance is attributed to a higher fraction of surface metallic Ru, as spark ablation under inert atmosphere typically yields metallic Ru nanoparticles. Additionally, Ru nanoparticles in the spark‐made catalyst are well‐distributed over both anatase and rutile TiO 2 , driven by Brownian motion and van der Waals adhesion. By contrast, Ru/TiO 2 ‐WI exhibits preferential Ru layer around rutile TiO 2 due to pre‐existing RuO 2 ‐rutile TiO 2 epitaxial interactions formed during calcination. This work highlights a sustainable approach for designing highly active low‐temperature CO 2 methanation catalysts, with potential versatility for broader catalytic applications.