Inexpensive and reusable transition metal heterogeneous catalysts exhibiting excellent catalytic performance represent an attractive alternative to noble metal and homogeneous catalysts. In this work, we fabricated a novel nanocatalyst comprised of Co nanoparticles (NPs) supported on a N-doped mesoporous carbon (Co/mCN-900) by simple one-pot pyrolysis of a homogeneous mixture of melamine, polyacrylonitrile, and Co(NO3)(2).6H(2)O under a N-2 atmosphere at 900 degrees C. The as-obtained Co/mCN-900 catalyst displayed a fluffy mesoporous structure with highly dispersed and accessible Co NPs acting as catalytic active sites. The Co/mCN-900 catalyst was effective in hydrogenating nitroarenes at milder conditions (i.e., 1 MPa H-2 and 120 degrees C) as compared to previously reported Co- and Ni-based catalysts. The Co/mCN-900 catalyst also catalyzed the reductive N-alkylation of nitroarenes with carbonyl compounds to form the corresponding aromatic secondary amines under very mild reaction conditions. In addition, the Co/mCN-900 catalyst showed good reusability since its morphology and activity were maintained after several reaction cycles. Therefore, this work provides a facile and promising method for fabricating non-precious transition metal-based catalysts with excellent performance and great potential for sustainable chemistry applications. (C) 2017 Elsevier Inc. All rights reserved.