CO Oxidation on Palladium . 2 . A Combined Kinetic - Infrared Reflection Absorption Spectroscopic Study of Pd ( 11 1 )
نویسندگان
چکیده
The oxidation of carbon monoxide was studied on a single-crystal Pd( 11 1) catalyst using an elevated pressure I R cell/ultrahigh vacuum surface analysis system. The reaction kinetics were followed a t elevated pressures by measuring the total pressure change during the course of reaction. In the temperature range of 500-570 K an apparent activation energy of 28.1 f 0.3 kcal/mol was determined, which agrees well with the 25 f 2 kcal/mol obtained for the heat of adsorption of CO on Pd( 11 1). Below 500 K the apparent activation energy decreases to 21 kcal/mol in concert with the decrease in the CO heat of adsorption.
منابع مشابه
Silica-Supported Palladium Particles with Infrared Reflection-Absorption Spectroscopy
The coadsorption of nitric oxide and carbon monoxide on Pd( loo), Pd( 11 l ) , and a model silica-supported palladium catalyst has been investigated with infrared reflection-absorption spectroscopy (IRAS) in the temperature range 100-500 K. The palladium surfaces were in equilibrium with a 1 X l P Torr equimolar mixture of CO and NO during the FT-IRAS studies. The structure and coverage of the ...
متن کاملAn Infrared and Kinetic Study of CO Oxidation on Model Silica - Supported Palladium Catalysts from to 15 Torr
The catalytic CO Oxidation on model silica-supported palladium catalysts has been investigateed with in situ infrared reflection-absorption spectroscopy (IRAS), temperature-programmed desorption/reaction, and kinetic measurements in the pressure range of lC9-15 Torr and the temperature range of 350-1000 K. The model catalysts were prepared by evaporating palladium onto a silica thin film suppor...
متن کاملKinetic study of ethanol and methanol electro-oxidation on Pd-vulcan XC-72R/Cu electrocatalyst in alkaline media
Abstract In this study , palladium nano-particles were electro deposited galvano - statically on carbon black powder (Vulcan XC -72R). The catalytic activity for electro - oxidation of ethanol and methanol in alkaline media were studied by cyclic voltammetry and linear sweep voltammetry techniques. The results indicated that the electro-oxidation of ethanol and methanol strongly depends o...
متن کاملCO adsorption and kinetics on well-characterized Pd films on Pt(111) in alkaline solutions
The electrochemistry of CO on a bare Pt(111) electrode as well as a Pt(111) electrode modified with pseudomorphic thin palladium films has been studied in alkaline solution by means of Fourier transform infrared (FTIR) spectroscopy. First Pd films were prepared and well characterized in UHV and subsequently transferred into the electrochemical cell for the registration of the voltammetric profi...
متن کاملMechanistic characterization of aerobic alcohol oxidation catalyzed by Pd(OAc)(2)/pyridine including identification of the catalyst resting state and the origin of nonlinear [catalyst] dependence.
The Pd(OAc)(2)/pyridine catalyst system is one of the most convenient and versatile catalyst systems for selective aerobic oxidation of organic substrates. This report describes the catalytic mechanism of Pd(OAc)(2)/pyridine-mediated oxidation of benzyl alcohol, which has been studied by gas-uptake kinetic methods and (1)H NMR spectroscopy. The data reveal that turnover-limiting substrate oxida...
متن کامل