Enhanced Light Alkane Oxidation under Impurity-Containing Conditions by Low-Coordinated Co–O Structures Boosting C–H Bond Activation
Fan Dang, Zeyu Jiang, Yadi Wang, Jialei Wan, Chunli Ai, Mingjiao Tian, Yanfei Jian, Han Xu, Reem Albilali, Jiaguo Yu, Chi He
Abstract
Anthropogenic light alkanes pose significant environmental and health hazards; however, achieving their efficient catalytic oxidation, particularly under industrial conditions with impurities, remains a huge challenge. Tuning the coordinated structure of metal atoms is a promising strategy for improving their low-temperature efficiency for stable C–H bond activation. Herein, we propose a one-step method for precisely modulating the coordination structures of Co atoms in a Co 3 O 4 catalyst by controlling the diverse nucleation rates of Co(OH) x species. The Co 3 O 4 -L catalyst with the lowest Co–O bonding exhibits exceptional catalytic performance, achieving complete oxidation of 1000 ppm propane and methane at just 179 and 290 °C, respectively. This performance is far superior to that of known catalysts, which typically require over 250 and 350 °C for 90% conversion of propane and methane, respectively. Additionally, Co 3 O 4 -L demonstrates excellent activity and stability in the presence of multiple organic components, as well as SO 2 and H 2 O. The promoted electron-pair interactions between σ/σ* C–H orbitals and d orbitals of low-coordinated Co 2+ species by sufficient low saturation sites strengthens the adsorption and activation of light alkanes and facilitates the cleavage of the C–H bond, ultimately reducing the reaction energy barrier. The high stability and antitoxicity are due to the abundant surface dangling bond-induced structural stability and rapid oxygen replenishment, which is facilitated by high electron transport capacity. This study establishes a solid foundation for further exploration of effective catalytic platforms for light alkanes under impurity-containing conditions.