Interaction of atomic hydrogen with monometallic Au(100), Cu(100), Pt(100) surfaces and surface of bimetallic Au@Cu(100), Au@Pt(100) overlayer systems: The role of magnetism

The spin-polarized calculations in generalized gradient approximation density–functional theory (GGA–DFT) have been used to show how the existence of second metals can modify the atomic hydrogen adsorption on Au (100), Cu (100), and Pt (100) surfaces. The computed adsorption energies for the atomic hydrogen adsorbed at the surface coverage of 0.125 ML (monolayer) for the monometallic Au (100), Cu (100), Pt (100) and bimetallic Au@Cu (100) and Au@Pt (100) surfaces are 3.98, 5.06, 4.13, 5.30, and 6.36 eV, respectively. Due to the adsorption of hydrogen atoms, the Au atoms of Au (100), Cu atoms of Cu (100), and Pt atoms of Au@Pt (100) surfaces tend to lose the 6s1, 4s1, and 6s1 electrons and reach the 5d10, 3d10, and 5d9 electronic configurations, respectively. In Pt (100), Au@Cu (100), and Au@Pt (100) systems, the spin-up and spin-down bands are asymmetric and shift significantly in opposite directions. Therefore, they are spin polarized; spin paramagnetism is also observed.