Adsorption of CO molecules on Rh low index and (331) stepped surfaces

Abstract

The 5-parameter Morse potential (for short 5-MP) of the interaction between C, 0 atom and Rh surface and the extended LEPS potential have been constructed, and the adsorption and diffusion of CO molecules on Rh low index surfaces and open rough Rh(331) stepped surface are investigated. This work puts forward the concept of vibration dactylogram property for molecular adsorption states. The calculation results and the analysis of vibration dactylogram show that there exists the commonness in the adsorption on Rh low index surfaces and Rh(331) stepped surface: with the increasing coverage, the top, bridge sites are adsorbed in perpendicularly in sequence, and the top sites are the steady adsorption sites and the bridge sites are the next. On (100) surface, CO molecules obtain the eigenvibration of 2009, 1946 cm-1 on the top and bridge sites respectively and the difference between the binding energy of above two sites is 0.09 eV; on (110) surface, CO molecules obtain the eigenvibration of 2019, 1961 cm-1 respectively; on (111) surface, CO molecules on the top, bridge and hollow sites produce the eigenvibration of 2000, 1912, 1894 cm-1 respectively, the binding energies of the three sites decrease in tum and the discrepancy between the top and bridge sites is 0.03 eV; on (331) surface, top and bridge sites between two equivalent top sites are adsorbed in, and then obtain the eigenvibration of2018, 1987 cm-\ 1969, 1927 cm-1 respectively.

Adsorption of Carbon Monoxide on Pt (335) and (112) Surfaces

“…The extended LEPS constructed by 5-MP is the credible potential function based on the experimental information of the interaction between CO and Pt. We have successfully studied CO adsorbed on Ni, Pt, Rh, and Pd and obtained results that agreed well with the experimental data. − …”

“…5-MP has been explained in the literature. − Here, it is stated briefly as follows: on the assumption that the metal cluster is frozen, the interaction energy U ( R⃗ ) is the 5-MP between an atom, for which the coordinate is specified by R⃗ . So, the whole metal surface cluster can be written in the form of a Morse potential U ( R⃗ ) = D ∑ i = 1 cluster ( h i + Q 1 R i + Q 2 ) { exp [ − 2 normalβ ( R i − R 0 ) ] − 2 .25em exp [ − normalβ ( R i − R 0 ) ] } 0.0ex0.0ex1em …”

“…In eq , there are five adjustable parameters: D , β, R 0 , Q 1 ,and Q 2 have been described in detailed in the literature. − The five adjustable parameters of the C−Pt and O−Pt systems obtained from the literature are listed in Table .…”

“…We have successfully studied CO adsorbed on Ni, Pt, Rh, and Pd and obtained results that agreed well with the experimental data. [24][25][26][27] 2. Extended LEPS Constructed by 5-MP and Cluster Models 2.1.…”

“…5-MP has been explained in the literature. [24][25][26][27] Here, it is stated briefly as follows: on the assumption that the metal cluster is frozen, the interaction energy U(R b ) is the 5-MP between an atom, for which the coordinate is specified by R b . So, the whole metal surface cluster can be written in the form of a Morse potential…”