Boosting CO Oxidation Activity of Ru/CeO2 via Ball Milling Activation

Three Ru/CeO2 samples are prepared using the deposition-precipitation method and then ball milled and subsequently calcined at 300 °C. It is demonstrated that the ball milling treatment results in a change of Ru valence and a strong interaction with CeO2 to form a Ru–O–Ce solid solution. The CO oxidation rate can be drastically improved with ball milling treatment. Specifically, comparing to 0.5Ru/CeO2, 0.5Ru/CeO2–BM demonstrates a 3-fold increase in activity at low reaction temperatures up to 100 °C. The superior activity of the ball-milled catalysts can be well correlated to the increase of oxygen vacancies on the catalyst surface. It is inferred that ball milling treatment is a promising approach to enhance the catalytic efficiency of Ru/CeO2 catalysts, which may provide valuable guidance for improving related catalytic systems.