Adsorption and diffusion behavior of hydrogen on the M-doped (M=Zr, Mo, Y, Cu, Pd, Ir, Mg, Al, Si) Ti(0001) surfaces: A first-principles study

•Influence mechanism of M dopants on the stability of Ti(0001) surface is elucidated.•All involved M dopants, especially Si, prevent H adsorption at Ti(0001) surfaces.•The penetration paths of H at M-doped Ti(0001) surfaces are predicted.•Mo promotes H in-plane diffusion on surface and Pd facilitates H penetration most significantly.