Yolk–shell microenvironment engineering enables Au/CuO@Void@mSiO 2 catalysts with high activity and cycling stability for glycerol oxidation to 1,3-dihydroxyacetone

an improved Stöber method combined with an adsorption-reduction strategy, and constructed as highly active and cycling-stable catalysts for base-free glycerol oxidation to DHA. A series of samples were prepared by adjusting the dosage of silica source, template, and precursor to tailor yolk-shell microenvironments. Among the prepared samples, the optimized catalyst, Au/CVmS-10, delivered 92.9% glycerol conversion with 91.3% selectivity toward DHA at 100 °C within 2 h. Notably, it maintained 89.1% conversion and 90.0% selectivity after five cycles, outperforming all previously reported base-free catalysts. Comprehensive characterization and analyses revealed that yolk-shell microenvironment engineering endowed the catalysts with excellent structural stability, high-specific-surface-area core-shell structure, rapid mass transfer, and enriched adsorbed oxygen species, as well as precisely tunable shell thickness, pore structure and interlayer void space, thus retaining outstanding catalytic performance throughout repeated cycling tests. This work highlights the microenvironment regulation within yolk-shell architectures as a key factor for enhancing both activity and durability in glycerol valorization.