Birnessite-type short rod-like MnO2 achieving propane low-temperature destruction: Benign synthesis strategy and reaction mechanism determination

作     者：Jian, Yanfei Feng, Xiangbo Tian, Mingjiao Jiang, Zeyu He, Chi 

作者机构：Xi An Jiao Tong Univ Sch Energy & Power Engn State Key Lab Multiphase Flow Power Engn Xian 710049 Shaanxi Peoples R China Univ Chinese Acad Sci Natl Engn Lab VOCs Pollut Control Mat & Technol Beijing 101408 Peoples R China 

出 版 物：《APPLIED SURFACE SCIENCE》 (应用表面科学)

年 卷 期：2021年第559卷

页      面：149905-149905页

核心收录：

学科分类：07[理学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 0702[理学-物理学] 

基　　金：National Natural Science Foundation of China [21876139, 21922606] Key R&D Program of Shaanxi Province [2019SF-244, 2019ZDLSF05-05-02] Shaanxi Natural Science Fundamental Shaanxi Coal Chemical Joint Fund [2019JLM-14] K. C. Wong Education Foundation Instrument Analysis Center of Xi'an Jiaotong University 

主　　题：MnO2 Oxygen vacancy Propane Catalytic oxidation Intermediates Activation route 

摘      要：Developing economical and robust noble metal-free materials for obstinate light alkane low-temperature decomposition is of great significance. Here, birnessite-type short rod-like MnO2 was firstly prepared by facile mixing KMnO4 and ascorbic acid under ambient conditions and employed in propane catalytic decomposition. Experimental results revealed that abundant oxygen vacancies and high valent Mn4+ species, superior reducibility, and high surface oxygen mobility guarantee the remarkable low-temperature activity of MnO2-SR, over which 90% of propane can be oxidized (T-90) at temperature as low as 225 degrees C, achieving a temperature reduction over 70 degrees C compared with that of delta-MnO2 (T-90 = 300 degrees C) and alpha-MnO2 (T-90 = 355 degrees C). In situ diffuse reflectance infrared Fourier transform spectroscopy revealed that the dissociation and activation of propane molecules is the decisive step in propane oxidation. Gaseous propane is slowly oxidized by adsorbed oxygen directly to the final mineralization products at low temperature region (200 degrees C) however, propane molecules are firstly dissociated and activated before oxidized to carbonate intermediate products over active oxygen, and then eventually oxidized to carbon dioxide and water.