New progress achieved in the design of metal oxide catalysts at the Institute of Chemical Physics, Chinese Academy of Sciences
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Recently, a team of associate researchers Sun Jian and Yu Jiafeng from the Institute of Carbon Resources, Small Molecules and Hydrogen Energy at the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, utilized the high-temperature quenching process of Flame Spray Pyrolysis (FSP) to lock the lattice oxygen in metal oxides in a metastable state, thereby significantly enhancing the activity of this lattice oxygen. As a result, the oxidation rate of CO was 10 times higher than that with traditional catalysts. The relevant research findings have been published online in Chemical Science.
Redox cycles involving lattice oxygen in oxides are widely present in catalytic oxidation reactions. Among them, the release rate of lattice oxygen is the rate-determining step of the reaction; therefore, enhancing the activity of lattice oxygen to accelerate the redox cycle is an important approach to promoting catalytic oxidation reactions. The team cleverly utilized high-temperature quenching to ensure the stable formation of oxide crystals while weakening the metal-oxygen interactions within the oxides, thereby placing the lattice oxygen in a supersaturated metastable state. No oxygen vacancies were found in the freshly prepared Ce-Zr solid solution oxides; metastable lattice oxygen could exist stably, while under relatively mild conditions (such as low-temperature reduction, vacuum treatment, metal loading, etc.), a large amount of reactive oxygen could be released, providing more active sites for the catalytic oxidation of CO. Studies have found that, compared to the Ce-Zr oxides prepared by the coprecipitation method, the oxides prepared using the FSP method can provide 19 times more oxygen vacancies. This research finding provides new insights for the design and application of novel oxide catalytic materials.