CO oxidation on Pd(1 1 1), Pt(1 1 1), and Rh(1 1 1) surfaces studied by infrared chemiluminescence spectroscopy

The infrared (IR) chemiluminescence studies of CO2 formed during steady-state CO oxidation over Pd(1 1 1), Pt(1 1 1), and Rh(1 1 1) surfaces were carried out. Analysis of their emission spectra indicates that the order of the average vibrational temperature ( T V AV ) values of CO2 formed during CO oxidation was as follows: Pd(1 1 1) > Pt(1 1 1) > Rh(1 1 1), and the order is coincident with the potential energy in the transition state expected by the theoretical calculations. Furthermore, it is suggested that the bending vibrational temperature ( T V B ) can also be influenced by the angle of O–C–O (∠OCO) of the activated complex in the transition state, which has also been proposed by the theoretical calculations.