Colloidal Solution Combustion Synthesis: Toward Mass Production of a Crystalline Uniform Mesoporous CeO₂ Catalyst with Tunable Porosity

Mesoporous metal oxides with uniform porosity are of considerable interest. Their economical production on a large scale in an efficient manner, however, remains a challenging task for commercialization. In this work, we demonstrate for the first time a scalable, economic, energy and time efficient method for the synthesis of a crystalline mesoporous CeO2 catalyst with tailored porosity, by utilizing colloidal SiO2 as a template. The size and amount of colloidal particles can tune the porosity of the CeO2 nanostructure as well as alter the heat transfer and heat balance of combustion. As-prepared CeO2 possesses uniform 22 nm pores and a 0.6 mL/g pore volume, which is the largest pore volume for CeO2 reported. The obtained mesoporous CeO2 catalyst exhibited excellent activity for soot and carbon monoxide oxidation. In principle, this method can be applied to synthesize different high-porosity crystalline oxides, and mesoporous CuO was also successfully prepared, thus demonstrating the generality of the method.