Density Functional Investigation of Methanol Dehydrogenation on Pd(111)

Abstract

Methanol dehydrogenation to CO and H on Pd(111) is systematically investigated using self-consistent periodic density functional theory (DFT). All possible intermediates involved are calculated. Methanol and formaldehyde adsorb weakly on the Pd(111) surface because they are saturated molecules. CO and H prefer 3-fold sites with the adsorption energies of 41.6 and 64.4 kcal/mol. CH 3 O binds stably at 3-fold and bridge sites. Most of the other intermediates are inclined to adsorb to the surface with the sp 3 configuration of the carbon atom and a hydroxyl-like configuration for O, i.e., top (η 1 -C) for CH 2 OH, bridge (η 2 -C) for CHOH, 3-fold (η 3 -C) for COH, bridge (η 1 -C-η 1 -O) for CH 2 O, and 3-fold (η 2 -C-η 1 -O) for CHO. All possible dehydrogenation pathways are calculated and four different routes via initial O-H and C-H bond scissions are found. The theoretical calculations indicate the initial C-H bond scission is more favorable for methanol decomposition, while O-H bond scission is preferable to C-H bond scission for CH 2 OH and CHOH, and the most possible dehydrogenation pathway on Pd(111) thus takes place via CH 3 OH f CH 2 OH f CH 2 O f CHO f CO.

Methanol adsorption on Pd(110) and Ag/Pd(110) studied by high-resolution photoelectron spectroscopy

“…7. A similar bonding geometry has been found in previous DFT calculations of methanol adsorption on Pd(111) [28,74,75], Ag(110) [76], and Ag(111) [77]. …”

Reaction mechanism of methyl nitrite dissociation during co catalytic coupling to dimethyl oxalate: A density functional theory study

“…The adsorption energy of H at the Fcc site is calculated to be -2.83 eV, which is 0.04 eV more negative that than at the Hcp site. In the most stable adsorption configuration, the H atom is exactly centered over the Fcc site with three equal H-Pd distances of 0.182 nm, which agrees well with the previous calculations [14,16].…”

A density functional theory study of methanol dehydrogenation on the PtPd 3 (111) surface

“…Previous slab model calculations indicated that CH 3 O preferred the three-fold fcc hollow site and the bridge site on pure Pt(111) [27] and pure Pd(111) [53], whereas the top site was not stable. However, the top, bridge, hcp and fcc sites were all found in this study, among which the fcc and hcp adsorptions were similar, and CeO bond was almost perpendicular to the surface.…”