Synergistic Effects of Crystal Phase and Strain for N Dissociation on Ru(0001) Surfaces with Multilayered Hexagonal Close-Packed Structures.

The synergistic effects of strain and crystal phase on the reaction activity of nitrogen molecule dissociation have been studied using density functional theory calculations on Ru(0001) surfaces with multilayered hexagonal close-packed structures. The phase transformation from hexagonal close-packed phase (2H) to face-centered cubic (3C) phase or unconventional phases (4H, DHCP, 6H, and 6H) would occur under the uniaxial tensile strain loaded along the axis. The close-packed surfaces of unconventional crystal phases show an enhanced chemical reactivity for N adsorption due to the upshifted -band center of Ru.

Selective hydrogenation of acetylene on Cu-Pd intermetallic compounds and Pd atoms substituted Cu(111) surfaces.

The selective hydrogenation of acetylene was studied on the ordered Cu-Pd intermetallic compounds (L1-type CuPd, L1-type CuPd, and L1-type CuPd) and Pd-modified Cu(111) surfaces through first-principles calculations. The catalytic selectivity and activity of Cu-Pd alloy catalysts are closely related to the crystal structure and composition of Cu-Pd intermetallic compounds and the size of Pd ensembles of Cu-based dilute alloy surface for the selective hydrogenation of acetylene to ethylene. Significantly, we found that the ordered Cu-Pd alloy surface containing isolated Pd atoms (i.