Interactions of H with tungsten carbide surfaces: An ab initio study

Abstract Adsorption of atomic hydrogen at several coverages on three WC surfaces with occupation of W and C sites is studied using a DFT formalism and generalized gradient approximation. In all three cases, at low coverage, the H adsorption over the W on top site is clearly favoured. Beyond this coverage, the surface occupation of both W and C sites become possible. The calculated adsorption energies Δ E indicate chemisorption. The evolution of the DOS with the coverage is reported. Our results are complemented by determination of surface energies for the (0 0 0 1), (1 0 −1 0) and (1 1 −2 0) surfaces.