Chinese Journal of Catalysis ›› 2016, Vol. 37 ›› Issue (6): 908-922.DOI: 10.1016/S1872-2067(16)62460-9

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Effects of Co3O4 nanocatalyst morphology on CO oxidation: Synthesis process map and catalytic activity

Liangpeng Zenga,b, Kongzhai Lia,b, Fan Huanga,b, Xing Zhua,b, Hongcheng Lia,b   

  1. a State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming 650093, Yunnan, China;
    b Faculty of Metallurgy and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, Yunnan, China
  • Received:2016-04-22 Revised:2016-05-05 Online:2016-05-30 Published:2016-05-30
  • Contact: Kongzhai Li
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (51374004, 51204083), the Candidate Talents Training Fund of Yunnan Province (2012HB009, 2014HB006), the Applied Basic Research Program of Yunnan Province (2014FB123), a School-Enterprise Cooperation Project from Jinchuan Corporation (Jinchuan 201115), and the Talents Training Program of Kunming University of Science and Technology (KKZ3201352038).

Abstract:

This study focuses on drawing a hydrothermal synthesis process map for Co3O4 nanoparticles with various morphologies and investigating the effects of Co3O4 nanocatalyst morphology on CO oxidation. A series of cobalt-hydroxide-carbonate nanoparticles with various morphologies (i.e., nanorods, nanosheets, and nanocubes) were successfully synthesized, and Co3O4 nanoparticles were obtained by thermal decomposition of the cobalt-hydroxide-carbonate precursors. The results suggest that the cobalt source is a key factor for controlling the morphology of cobalt-hydroxide-carbonate at relatively low hydrothermal temperatures (≤ 140 ℃). Nanorods can be synthesized in CoCl2 solution, while Co(NO3)2 solution promotes the formation of nanosheets. Further increasing the synthesis temperature (higher than 140 ℃) results in the formation of nanocubes in either Co(NO3)2 or CoCl2 solution. The reaction time only affects the size of the obtained nanoparticles. The presence of CTAB could improve the uniformity and dispersion of particles. Co3O4 nanosheets showed much higher catalytic activity for CO oxidation than nanorods and nanocubes because it has more abundant Co3+ on the surface, much higher reducibility, and better oxygen desorption capacity.

Key words: Cobalt oxide nanocatalyst, Synthesis process map, Morphology effect, Catalytic activity, Carbon monoxide oxidation