Single-metal-adatom catalysts for the synthesis of 2D carbon nitride metal-coordinated networks

Abstract

Metal-coordinated networks have been found to be excellent catalyst for environmental purposes, such as green hydrogen generation or photo-degradation of pollutants. Recently, its traditional three-dimensional structure has been extended to two dimensions. However, the synthesis and stability of these networks in their 2D form remains a challenge. We have designed, characterized and synthesized, using a bottom-up approach, a 2D metal-coordinated network combining melamine molecules and thermally generated native copper adatoms on a Cu(110) substrate at 600 K. As a result, we have obtained a 2D hexagonal carbon nitride Cu-coordinated network. We demonstrate that the underlying mechanism of its formation involves partial dehydrogenation and subsequent metalation of amino groups. We prove the crucial role of copper adatoms in the formation, serving as heterogeneous metal-site catalysts, as well as in the further stabilization of the network. The obtained metal-coordinated network is indeed a single atom catalyst with high potential in technological applications.