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

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 ΔE 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.