Phase Engineering of Amorphous Ru-O-C₆₀ for Efficient Electrosynthesis of Sulfoxides.

Abstract

The diverse short/medium-range structures of amorphous nanomaterials dictate their phase structures, which ultimately govern their catalytic behaviors. However, the inherent high Gibbs free energy caused by disordered atomic arrangement makes the controlled phase regulation of amorphous nanomaterials challenging. Herein, we regulated the phase structure of amorphous RuO_x nanosheets by constructing a novel amorphous Ru-O-C₆₀ motif. Integrated differential phase contrast image confirms the incorporation and spatial distribution of C₆₀ within the amorphous RuO_x nanosheets. X-ray absorption fine structure measurements reveal that amorphous RuO_x nanosheets anchored onto C₆₀ (A-RuO_x/C₆₀ NSs) possess an edge-sharing RuO₆ octahedral configuration. The A-RuO_x/C₆₀ NSs exhibit outstanding performance in the electro-oxidation of methyl phenyl sulfide, achieving 99.1% conversion, 99.63% selectivity, 99.57% Faradaic efficiency, and excellent stability over 50 cycles, while maintaining high conversion and selectivity toward various para- and meta-substituted methyl phenyl sulfide derivatives. Density functional theory calculations reveal that the edge-sharing RuO₆ octahedral configuration enhances methyl phenyl sulfide adsorption, facilitate Ru─O bond cleavage and S═O bond formation, thereby accelerating product formation and release. Moreover, the synthesis strategy is extendable to the preparation of various monometallic and bimetallic amorphous oxides/C₆₀ nanosheets.