Promotional effect of cobalt doping on catalytic performance of cryptomelane-type manganese oxide in toluene oxidation  

作　　者：Ning Dong Mengyue Chen Qing Ye Dan Zhang Hongxing Dai 

机构地区：[1]Key Laboratory of Beijing on Regional Air Pollution Control,Department of Environmental Science,School of Environmental and Chemical Engineering,Faculty of Environment and Life,Beijing University of Technology,Beijing 100124,China [2]R&D Department of Atmospheric Prevention and Control Technology,Guangdong Suncere Technology Co.,Ltd.,Guangzhou 510220,China [3]Beijing Key Laboratory for Green Catalysis and Separation,Key Laboratory of Beijing on Regional Air Pollution Control,Key Laboratory of Advanced Functional Materials,Education Ministry of China,and Laboratory of Catalysis Chemistry and Nanoscience,Department of Environmental Chemical Engineering,School of Environmental and Chemical Engineering,Faculty of Environment and Life,Beijing University of Technology,Beijing 100124,China

出　　处：《Journal of Environmental Sciences》2023年第4期263-274,共12页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (Nos. 21277008 and 20777005);National Key Research and Development Program of China (No. 2017YFC0209905)。

摘　　要：The cryptomelane-type manganese oxide (OMS-2)-supported Co (x Co/OMS-2;x=5,10,and15 wt.%) catalysts were prepared via a pre-incorporation route.The as-prepared materials were used as catalysts for catalytic oxidation of toluene (2000 ppmV).Physical and chemical properties of the catalysts were measured using the X-ray diffraction (XRD),Fourier transform infrared spectroscopic (FT-IR),scanning electron microscopic (SEM),X-ray photoelectron spectroscopy (XPS),and hydrogen temperature-programmed reduction (H_(2)-TPR)techniques.Among all of the catalysts,10Co/OMS-2 performed the best,with the T90%,specific reaction rate at 245℃,and turnover frequency at 245℃ (TOFCo) being 245℃,1.23×10^(-3)moltoluene/(gcat·sec),and 11.58×10^(-3)sec-1for toluene oxidation at a space velocity of 60,000mL/(g·hr),respectively.The excellent catalytic performance of 10Co/OMS-2 were due to more oxygen vacancies,enhanced redox ability and oxygen mobility,and strong synergistic effect between Co species and OMS-2 support.Moreover,in the presence of poisoning gases CO_(2),SO_(2)or NH_(3),the activity of 10Co/OMS-2 decreased for the carbonate,sulfate and ammonia species covered the active sites and oxygen vacancies,respectively.After the activation treatment,the catalytic activity was partly recovered.The good low-temperature reducibility of 10Co/OMS-2 could also facilitate the redox process accompanied by the consecutive electron transfer between the adsorbed O_(2)and the cobalt or manganese ions.In the oxidation process of toluene,the benzoic and aldehydic intermediates werefirst generated,which were further oxidized to the benzoate intermediate that were eventually converted into H_(2)O and CO_(2).

关 键 词：Cryptomelane-type manganese OXIDE Cobalt doping Volatile organic compound Toluene oxidation 

分 类 号：X701[环境科学与工程—环境工程]