Acid Etching-Induced In Situ Growth of λ-MnO2 over CoMn Spinel for Low-Temperature Volatile Organic Compound Oxidation

• DOI: 10.1021/acs.est.2c02483
• Publication Date: 2022-06-16T20:31:37Z
• Authors: Cangpeng Shan; Yan Zhang; Qian Zhao; Kaixuan Fu; Yanfei Zheng; Rui Han; Caixia Liu; Na Ji; Weichao Wang; Qingling Liu
• Keywords: 01 natural sciences; 0104 chemical sciences

Surface lattice oxygen is crucial to the degradation of volatile organic compounds (VOCs) over transition metal oxides according Mars-van Krevelen mechanism. Herein, λ-MnO2 in situ grown on surface CoMn spinel was prepared by acid etching corresponding catalysts (CoMn-Hx-Ty) for VOC oxidation. Experimental and relevant theoretical exploration revealed that could decrease electron cloud density around O atom weaken adjacent Mn-O bond due fracture Co-O bond, facilitating transfer subsequently activation oxygen. The obtained CoMn-H1-T1 exhibited an excellent catalytic performance with a 90% acetone conversion at 149 °C, which 42 °C lower than spinel. Furthermore, partially maintained structure led better stability pure λ-MnO2. In diffuse reflectance infrared Fourier transform spectroscopy confirmed possible pathway where adsorptive converted into formate acetate species CO2, consumption identified as rate-limiting step. This strategy can improve activating oxygen, broaden their application