Rice Husk-Derived Carbon-Coated Silica Hybrid Nanospheres with Tunable Wettability for Cost-Effective and Efficient Pickering Emulsion Catalysis

The high-value and refined utilization of biomass is of great significance, but its cost-effectiveness still faces enormous challenges. The carbon-coated silica nanospheres (SiO 2 @C) with well-tunable wettability were synthesized through a smart pH-controlled sol–gel/self-assembly approach from rice husks, which function as both renewable carbon and silicon sources. The prepared SiO 2 @C supported Ru catalysts (Ru/SiO 2 @C) with well-tunable wettability and well-modulated size distribution are active and selective for Pickering interfacial catalysis (PIC), demonstrated by the efficient vanillin hydrodeoxygenation (HDO). Metal–support interactions in Ru/SiO 2 @C and HDO mechanisms were revealed by computational simulation. Results suggest the existence of multiple HDO mechanisms of vanillyl alcohol over different reaction sites and the potential support–reactant interaction promoting the HDO of vanillyl alcohol. Our work provides an important perspective for the fancy design of cost-effective and efficient catalysts for PIC and highlights the profound value of biomass-derived materials for future energy utilization.