Kinetic Analysis of High-Rate and of Low-Rate Regimes in CO Oxidation on Pt Group Metals: Evidence for Vibrational Excitation of the O-Rich Adlayer and for Thermal Equilibrium of the CO-Rich Phase
-
Ettore Molinari
Abstract
Proper reduction of available literature data on the heterogeneous CO+O2 reaction on Pt group metals allows one to describe the parallel process of CO desorption, in extended intervals of temperature and gas composition, both in the High-Rate regime of an oxygen rich surface and in the Low-Rate regime of a CO rich surface. The outcome of this analysis is the determination of “apparent” as well as of “true” activation energies for both CO oxidation and desorption and their dependence on surface coverage by O or by CO-adspecies. The conclusion is reached that non-equilibrium conditions of vibrational excitation of the adlayers prevail in the HR regions, while Boltzmann equilibrium characterizes LR regimes in extended temperature and pressure intervals. These results have been discussed in the framework of a theoretical model that predicts hyperthermal vibrational states of the adlayer, which depend on the efficiency of energy dissipation into the metal.
© by Oldenbourg Wissenschaftsverlag, Roma, Germany
Artikel in diesem Heft
- Kinetic Analysis of High-Rate and of Low-Rate Regimes in CO Oxidation on Pt Group Metals: Evidence for Vibrational Excitation of the O-Rich Adlayer and for Thermal Equilibrium of the CO-Rich Phase
- Effect of Particle Size on Non-Isothermal Decomposition of Potassium Titanium Oxalate
- Inelastic Neutron Scattering (INS) Study of Low Frequency Vibrations and Hydrogen Bonding of (E)-2-Hydroxyimino-2-Cyanoacetic Acid Ethyl Ester
- Electrochemical and in situ Spectroelectrochemical Properties of Phthalocyanines Bearing N-Benzyl-4-Phenyloxyacetamide Moieties
- Initial State and Transition State Contributions to Reactivity Trends of Base-Catalyzed Hydrolysis of Some Nitro Chromen-2-One Derivatives
- Studies on the Kinetics of Tetraethylammonium Bromochromate Oxidation of Some Meta- and Para-Substituted Benzyl Alcohols in Non-Aqueous Media
- Protonation of Benzo-18-crown-6: Extraction and DFT Study
- Contribution to the Complexation of some Univalent Metal Cations with p-Tert-Butylcalix[4]arene-Tetrakis(N,N-Diethylacetamide) in Nitrobenzene Saturated with Water
Artikel in diesem Heft
- Kinetic Analysis of High-Rate and of Low-Rate Regimes in CO Oxidation on Pt Group Metals: Evidence for Vibrational Excitation of the O-Rich Adlayer and for Thermal Equilibrium of the CO-Rich Phase
- Effect of Particle Size on Non-Isothermal Decomposition of Potassium Titanium Oxalate
- Inelastic Neutron Scattering (INS) Study of Low Frequency Vibrations and Hydrogen Bonding of (E)-2-Hydroxyimino-2-Cyanoacetic Acid Ethyl Ester
- Electrochemical and in situ Spectroelectrochemical Properties of Phthalocyanines Bearing N-Benzyl-4-Phenyloxyacetamide Moieties
- Initial State and Transition State Contributions to Reactivity Trends of Base-Catalyzed Hydrolysis of Some Nitro Chromen-2-One Derivatives
- Studies on the Kinetics of Tetraethylammonium Bromochromate Oxidation of Some Meta- and Para-Substituted Benzyl Alcohols in Non-Aqueous Media
- Protonation of Benzo-18-crown-6: Extraction and DFT Study
- Contribution to the Complexation of some Univalent Metal Cations with p-Tert-Butylcalix[4]arene-Tetrakis(N,N-Diethylacetamide) in Nitrobenzene Saturated with Water
