A Monolayer Carbon Nitride on Au(111) with a High Density of Single Co Sites.

Carbon nitrides that expose atomically dispersed single-atom metals in the form of M-N-C (M = metal) sites are attractive earth-abundant catalyst materials that have been demonstrated in electrocatalytic conversion reactions. The catalytic performance is determined by the abundance of N-doped sites and the type of metal coordination to N, but challenges remain to synthesize pristine carbon nitrides with a high concentration of the most active sites and prepare homogeneously doped materials that allow for in-depth characterization of the M-N-C sites and quantitative evaluation of their catalytic performance. Herein, we have synthesized and characterized a well-defined monolayer carbon nitride phase on a Au(111) surface that exposes an exceedingly high concentration of Co-N sites.