Cobalt nanoparticles embedded in a porous carbon matrix as an efficient catalyst for ammonia decomposition

A metallic Co nanoparticle catalyst embedded in a carbon matrix was synthesized through a facile solvothermal method and subsequent thermal treatment. The synthesized Co–C precursors were calcined in N2 and limited air atmosphere respectively, which were applied for ammonia decomposition. It was found that different thermal treatments have a significant effect on the catalyst microstructure, particle size, components and catalytic performance. Compared to the Co@C-700-N sample obtained in N2 flow, the CoOx@C-700-A catalyst obtained in limited air atmosphere showed better activity with a ∼55% NH3 conversion (500 °C and GHSV = 15 000 h−1). Moreover, the structure sensitivity of NH3 decomposition over Co catalysts is proposed over a series of CoOx@C-A catalysts. With an increase of Co particle size, the catalytic activity showed an obvious decrease.