Quantum chemistry and in situ FTir spectroscopy studies on potential-dependent properties of CO adsorbed on Pt electrodes

✍ Scribed by Wen-Feng Lin; Shi-Gang Sun; Zhong-Qun Tian; Zhao-Wu Tian

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 722 KB
• Volume: 38
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(93)80220-t

✦ Synopsis

The electronic and vibrational properties of CO adsorbed on Pt electrodes at different potentials have been studied, by using methods of self-consistent-charge discrete variational Xa (SCC-DV-Xa) cluster calculations and in situ FTir spectroscopy. Two new models have been developed and verified to be successful: (1) using a "metallic state cluster" to imitate a metal (electrode) surface; and (2) charging the cluster and shifting its Fermi level (er) to simulate, according to the relation of -der = e dE, quantitatively the variation of the electrode potential (R). It is shown that the binding of Pt-CO is dominated by the electric charge transfer of dx, = 2x,$, , while that of uco = Pt is less important in this binding. The electron occupancy of the 2x* orbital of CO, weakens the C-0 bond and decreases the vco. Variation of E mainly influences the charge transfer process of dn, 3 2x&, , but hardly influences that of oo, + Pt. A linear potential-dependence of v, has been shown and the calculated dv,-JdE = 35.0~m-' V-'. All results of calculations coincide with the ir experimental data.