Acta Physico-Chimica Sinica ›› 2019, Vol. 35 ›› Issue (9): 923-939.doi: 10.3866/PKU.WHXB201810002

Special Issue: 碳氢键活化

• Review • Previous Articles     Next Articles

Research Progress on the Photocatalytic Conversion of Methane and Methanol

Shuyi ZHANG1,2,Jingxian BAO1,3,Bo WU1,2,Liangshu ZHONG1,4,*(),Yuhan SUN1,4,*()   

  1. 1 CAS Key Laboratory of Low-Carbon Conversion Science and Engineering, Shanghai Advanced Research Institute
    2 Chinese Academy of Sciences, Shanghai 201203, P. R. China
    3 University of the Chinese Academy of Sciences, Beijing 100049, P. R. China
    4 College of Sciences, Shanghai University, Shanghai 200444, P. R. China
  • Received:2018-10-08 Published:2018-11-26
  • Contact: Liangshu ZHONG,Yuhan SUN E-mail:zhongls@sari.ac.cn;sunyh@sari.ac.cn
  • Supported by:
    This work was supported by the National Key R & D Program of China(2017YFB0602202);This work was supported by the National Key R & D Program of China(2018YFB0604700);National Natural Science Foundation of China(21573271);National Natural Science Foundation of China(91545112);National Natural Science Foundation of China(21703278);Key Research Program of Frontier Sciences, CAS(QYZDB-SSW-SLH035);"Transformational Technologies for Clean Energy and Demonstration" and Strategic Priority Research Program of the Chinese Academy of Sciences(XDA21020600)

Abstract:

With the increasing energy demands and the limited petroleum reserves, it is highly desirable to produce fuels and chemicals from non-petroleum feedstocks, such as coal, natural gas and biomass. Catalytic conversion of C1 resources (CO, CO2, CH3OH, CH4, etc.) affords various products and attracts increasing attention from both academia and industries. Methane and methanol are important C1 feedstocks in the production of fuels and chemicals. In order to obtain high selectivity for the target product, it is necessary to control the activation of C―H bonds in methane and methanol. However, this remains a great challenge. Although the traditional thermal catalytic conversion of methane and methanol has been developed over decades, there are still some disadvantages associated with the catalytic process, such as harsh reaction conditions, high energy consumption, and low selectivity. Photocatalysis, which is driven by photoenergy, can compensate for the Gibbs free energy. In the photocatalytic reactions, semiconductor photocatalysts absorb photons and generate electrons and holes in their conduction and valence bands, respectively, to accelerate the reaction rate. The position of the conduction band determines the oxidation capacity, and the bandgap determines the light absorption property. Normally, the oxidation capacity of photocatalysts is regulated by choosing semiconductors with a suitable bandgap or anions/cations doping. Fabrication of heterojunction and loading metalsare recognized as effective methods to promote the separation of electron-hole pairs and improve the photocatalytic efficiency. In contrast to thermal catalysis, photocatalysis can be carried out under mild reaction conditions with low energy consumption. Recently, photocatalysis has been considered an attractive route for the efficient conversion of methane and methanol to fuels and chemicals. Partial oxidation of methane, which is necessary to avoid the formation of byproducts, can be achieved by adjusting the wavelength and intensity of the light and the oxidation capacity of the photocatalysts. In addition, light-induced plasmon resonance improves the efficiency of methane conversion by forming an intrinsic high-energy magnetic field that can polarize methane. In methanol conversion, the C―H bond can be selectively activated, instead of the O―H bond, by light irradiation. Therefore, C―C coupling can be realized for the production of various value-added chemicals from methanol. This review summarizes the recent advances in the photocatalytic conversion of methane and methanol including the reactions of reforming, oxidation, and coupling. Perspectives and challenges for further research on the photocatalytic conversion of methane and methanol are also discussed.

Key words: Activation of C―H bond, C1 chemistry, Methane, Methanol, Photocatalysis

MSC2000: 

  • O644