Bo Hyeon Hwang  Eun Duck Park

Vol. 31,  No. 2, pp. 120-130, Jun.  2025
10.7464/ksct.2025.31.2.120

Hydrogen Ammonia decomposition Co catalyst Carbon support CoNi bimetal

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There is increasing interest in using hydrogen as a carbon-free fuel. In particular, hydrogen production through the decomposition of ammonia has been actively studied because ammonia is considered a realistic hydrogen carrier for importing hydrogen from abroad. In this article, the activity of cobalt catalysts supported on various carbon supports was evaluated in terms of ammonia decomposition. Carbon nanotubes (CNT), graphitic nanofibers (GNF), graphite, activated carbon (AC), and carbon black (CB) were used as carbon supports. The ammonia conversion decreased in the order of Co/CNT ~ Co/GNF > Co/Graphite >> Co/AC > Co/CB under reaction conditions with 25% ammonia. When comparing the turnover frequency (TOF) considering the number of active sites on the cobalt catalysts, it decreased in the order of Co/CNT > Co/GNF ~ Co/Graphite >> Co/AC ~ Co/CB. In addition, to check the catalytic performance of non-precious bimetals, CoNi alloy catalysts supported on GNF were compared. The ammonia conversion decreased in the order of 10 wt% Co/GNF ~ 2.5 wt% Ni-7.5 wt% Co/GNF > 5 wt% Ni-5 wt% Co/GNF > 7.5 wt% Ni-2.5 wt% Co/GNF > 10 wt% Ni/GNF. Based on the above results, it can be concluded that the dispersion of the cobalt catalyst is the main variable for the ammonia decomposition reaction, but in the case of CoNi alloy catalysts, the interaction between the metals is also important.