Hierarchically interconnected porous MnxCo3-xO4 spinels for Low-temperature catalytic reduction of NO by CO

Developing efficient catalysts for low reaction-temperature catalytic reduction of NO by CO (CO-DeNO(x)) is desirable but very challenging. Here, we report that hierarchically interconnected porous (HIP) MnxCo3-xO4 spinels, synthesized by a facile citric acid-assisted sol-gel method, can act as highly efficient catalysts for CO-DeNO(x). The obtained Mn0.3Co2.7O4 displayed a much-enhanced catalytic performance with 87% NO removal at 100 degrees C and a wide active-temperature window (100-400 degrees C). Its superior activity stems from the following reasons: (i) the high-valence of Mn3+, Mn4+, and Co3+ species in the Co-O-Mn structure enables the high catalytic activity and the effective redox-cycling of the Co3+ and Co2+ adsorption sites; (ii) the HIP structure can significantly enhance gas diffusion. This work offers an avenue to design metal oxide catalysts for CO-DeNO(x) by effectively controlling the doping metal concentration and oxidation states of the active components. (C) 2022 Elsevier Inc. All rights reserved.

Automated summary

Hierarchically interconnected porous (HIP) MnxCo3-xO4 spinels synthesized by a facile citric acid-assisted sol-gel method show high efficiency as catalysts for CO-DeNO(x), with a wide active-temperature window and enhanced catalytic performance.