Confined Mn^(2+) enables effective aerobic oxidation catalysis  

作　　者：Desheng Yuan Sicong Ma Xiao Kong Chi Zhang Lin Chen Chengsheng Yang Lihua Wang Zhen Liu Lin Ye Yongmei Liu Rui Ma Zhi-Pan Liu Yifeng Zhu Yong Cao Xinhe Bao 

机构地区：[1]Department of Chemical Physics,University of Science and Technology of China,Hefei 230026,China [2]Department of Chemistry,Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials,Collaborative Innovation Center of Chemistry for Energy Materials,Fudan University,Shanghai 200438,China [3]Key Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional Molecules,Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences,Shanghai 200032,China [4]School of Materials and Chemistry,University of Shanghai for Science and Technology,Shanghai 200093,China [5]Shanghai Synchrotron Radiation Facility,Shanghai Advanced Research Institute,Chinese Academy of Sciences,Shanghai 201204,China [6]Institute of Advanced Fluorine-Containing Materials,Zhejiang Normal University,Jinhua 321004,China [7]State Key Laboratory of Catalysis,National Laboratory for Clean Energy,Collaborative Innovation Center of Chemistry for Energy Materials,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,China

出　　处：《Science China Chemistry》2024年第5期1545-1553,共9页中国科学（化学英文版）

基　　金：supported by the Ministry of Science and Technology of China (2022YFA1503804);National Natural Science Foundation of China (22272031, 22102033);Science&Technology Commission of Shanghai Municipality (22ZR1408000, 22QA1401300);the Fundamental Research Funds for the Central Universities (20720220008)。

摘　　要：Effective and mild activation of O_(2) is essential but challenging for aerobic oxidation. In heterogeneous catalysis, high-valence manganese oxide(e.g., +4) is known to be active for the oxidation, whereas divalent MnO is ineffective due to its limited capacity to supply surface oxygen and its thermodynamically unstable structure when binding O_(2) in reaction conditions. Inspired by natural enzymes that rely on divalent Mn^(2+), we discovered that confining Mn^(2+) onto the Mn_(2)O_(3) surface through a dedicated calcination process creates highly active catalysts for the aerobic oxidation of 5-hydroxymethylfurfural, benzyl alcohol, and CO.The Mn_(2)O_(3)-confined Mn^(2+) is undercoordinated and efficiently mediates O_(2) activation, resulting in 2–3 orders of magnitude higher activity than Mn_(2)O_(3) alone. Through low-temperature infrared spectroscopy, we distinguished low-content Mn^(2+) sites at Mn_(2)O_(3) surface, which are difficult to be differentiated by X-ray photoelectron spectroscopy. The combination of in-situ energydispersive X-ray absorption spectroscopy and X-ray diffraction further provides insights into the formation of the newly identified active Mn^(2+) sites. By optimizing the calcination step, we were able to increase the catalytic activity threefold further.The finding offers promising frontiers for exploring active oxidation catalysts by utilizing the confinement of Mn^(2+)and oftenignored calcination skills.

关 键 词：confinement catalysis manganese oxide aerobic oxidation divalent Mn^(2+) operando spectroscopies 

分 类 号：O643.36[理学—物理化学]