Chinese Journal of Catalysis ›› 2020, Vol. 41 ›› Issue (11): 1734-1744.DOI: 10.1016/S1872-2067(20)63599-9

• Articles • Previous Articles     Next Articles

Sodium-treated sepiolite-supported transition metal (Cu, Fe, Ni, Mn, or Co) catalysts for HCHO oxidation

Ning Donga, Qing Yea, Mengyue Chena, Shuiyuan Chenga, Tianfang Kanga, Hongxing Daib   

  1. a Key Laboratory of Beijing on Regional Air Pollution Control, Department of Environmental Science, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China;
    b Beijing Key Laboratory for Green Catalysis and Separation, Key Laboratory of Beijing on Regional Air Pollution Control, and Laboratory of Catalysis Chemistry and Nanoscience, Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China
  • Received:2020-02-26 Revised:2020-03-31 Online:2020-11-18 Published:2020-08-15
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (21277008 and 20777005), National Key Research and Development Program of China (2017YFC0209905), and Natural Science Foundation of Beijing (8082008).

Abstract: Sodium-treated sepiolite (NaSep)-supported transition metal catalysts (TM/NaSep; TM=Cu, Fe, Ni, Mn, and Co) were synthesized via a rotary evaporation method. Physicochemical properties of the as-synthesized samples were characterized by means of various techniques, and their catalytic activities for HCHO (0.2%) oxidation were evaluated. Among the samples, Cu/NaSep exhibited superior performance, and complete HCHO conversion was achieved at 100℃ (GHSV=240000 mL/(g·h)). Additionally, the sample retained good catalytic activity during a 42 h stability test. A number of factors, including elevated acidity, the abundance of oxygen species, and favorable low-temperature reducibility, were responsible for the excellent catalytic activity of Cu/NaSep. According to the results of the in-situ DRIFTS characterization, the HCHO oxidation mechanism was as follows:(i) HCHO was rapidly decomposed into dioxymethylene (DOM) species on the Cu/NaSep surface; (ii) DOM was then immediately converted to formate species; (iii) the resultant formate species were further oxidized to carbonates; (iv) the carbonate species were eventually converted to CO2 and H2O.

Key words: Sodium-treated sepiolite, Transition metal loading, Supported transition metal catalyst, Volatile organic compound, HCHO oxidation