High-performance CoCe catalyst constructed by the glucose-assisted in-situ reduction for CH4/CO2 dry reforming

Abstract

In this paper, the CoCe catalysts, which were prepared using a glucose-assisted in-situ reduction method, used to the CO2/CH4 dry reforming (DRM). The physicochemical properties of the prepared catalysts were investigated by H2-TPR, XRD, BET, Quasi in-situ XPS and CO2-TPD. The findings revealed that the metal Co was the primary active species in the DRM reaction. The good interaction between Ce and Co species can effectively promote the precursors to be reduced to form the active Co0 species and oxygen vacancies, which can also effectively inhibit the Co0 species to be sintered. The metal Co crystallinity and crystal size, active Co0 centers and oxygen vacancies can be successfully constructed by the glucose-assisted method. With the introduction of the glucose promoter, the crystal size of the corresponding catalyst metal Co decreased from 23.21 nm to 18.67 nm, the active Co0 species content on the catalyst surface increased from 41.3 % to 45.7 %, and the adsorbed oxygen content on the surface increased from 20.0 % to 23.0 %. Besides, the glucose promoter can affect the electronic effects of Co-Ce species to promote the DRM reaction. The CoCe3-G catalyst with a Co/Ce mole ratio of 3.0 exhibited the best reforming catalytic performances, and the CH4 and CO2 conversion was 87.2 % and 54.0 % at atmospheric pressure and 700 °C, respectively. Meanwhile, the CoCe3-G catalyst exhibited excellent reforming catalytic stability.