Direct reduction of NO into N₂ catalyzed by fullerene-supported rhodium clusters

Catalytic conversion of NO has long been a focus of atmospheric pollution control and diesel vehicle exhaust treatment. Rhodium is one of the most effective metals for catalyzing NO reduction, and understanding the nature of the active sites and underlying mechanisms can help improve the design of Rh-based catalysts towards NO reduction. In this work, we investigated the detailed catalytic mechanisms for the direct reduction of NO to N₂ by fullerene-supported rhodium clusters, C₆₀Rh₄⁺, with density functional theory calculations. We found that the presence of C₆₀ facilitates the smooth reduction of NO into N₂ and O₂, as well as their subsequent desorption, recovering the catalyst C₆₀Rh₄⁺. Such a process fails to be completed by free Rh₄⁺, emphasizing the critical importance of C₆₀ support. We attribute the novel performance of C₆₀Rh₄⁺ to the electron sponge effect of C₆₀, providing useful guidance for designing efficient catalysts for the direct reduction of NO.