Scalable synthesis of ordered mesoporous binary metal oxide: CexZr1-xO2 as thermally stable catalyst for enhanced CO oxidation

Abstract

The scale-up synthesis of mesoporous binary metal oxides with uniform porosity for practical application is still challenging. Here we report an ordered mesoporous CexZr1-xO2 catalyst synthesized by a scalable colloidal solution combustion method, and tested for CO oxidation. The mesoporous CexZr1-xO2 catalyst is durable and demonstrates superior CO oxidation activity with a full conversion at ∼ 400 °C due to its high surface area of about 141 m2/g and pore volumes of 0.55 mL/g. The CexZr1-xO2 catalyst is also active and thermally stable up to 800 °C. Its structure is robust with uniform Zr distribution and nano-cavities even after accelerated ageing. We have also realized the practical feasibility by scale-up synthesis of 600 g mesoporous CexZr1-xO2 catalyst. It is then effectively applied as diesel oxidation catalysts in a Diesel Particulate Filter (DPF) in simulated vehicle gas environment. Our DPF prototype allows nearly a full CO to CO2 conversion below 100 °C. The synthesis is simple and scalable, allowing full control of composition and porosity to effectively design binary oxides for enhanced catalytic applications.