▎ 摘　　要

Cobalt and nitrogen co-doped carbon (Co/N/C) catalysts prepared by pyrolysis are promising electrocatalysts for hydrogen evolution reaction (HER). Construction of Co-N-x active sites is an important strategy for improving HER activity. We developed a method for thermally controlled construction of the Co-N-x active sites by applying a bottom-up synthetic methodology using an N-doped graphene nanoribbon (N-GNR). Preorganized aromatic rings in the precursors assist graphitization during generation of N-GNR which has N2 sites that coordinate to a cobalt ion. Atomically dispersed Co-N-x sites in the catalysts are observed by electron microscopy. Moreover, the amount of Co-N-x sites increases up to 0.31 wt% as confirmed by XPS and elemental analysis. The Co/N/C catalyst prepared from the precisely designed precursor forming an NGNR shows HER activity with a low overpotential of 258mV (in 1.0M HClO4aq) and 311mV (in 0.1M HClO4aq) at 10 mA.cm(-2), and with a long-term stability.