Facile synthesis of Co3O4@SiO2/Carbon Nanocomposite Catalysts from Rice Husk for Low-Temperature CO Oxidation

Co3O4 was synthesized in the presence of 3D porous nanostructured SiO2/carbon composite derived from rice husk via a hydrothermal method to produce Co3O4@SiO2/C nanostructures with good microstructural, morphological and excelling catalytic properties. The morphology and textural properties of the products were tuned by using different amounts of hydrocarbonized rice husk. TEM images exhibited nanoclusters 1–9 nm in diameter and reducing the nanoparticle size of Co3O4 by adding hydrocarbonized rice husk. The specific surface area value of Co3O4@SiO2/C is 115 m2 /g which is significantly improved as compared to Co3O4 prepared in the absence of hydrocarbonized rice husk (70 m2 /g). Materials were tested in the oxidation of CO oxidation as model reaction. Compared to conventional Co3O4 nanoparticles, as-prepared Co3O4@SiO2/C exhibited a superior catalytic activity for CO oxidation, i.e., T50 (50% conversion) is at <25 °C (at 100°C for Co3O4). © 2021