Platinum surfaces temperature-programmed desorption

Figure 7.7. Temperature-programmed desorption measurements corresponding to zero-, first-, and second-order kinetics of silver from ruthenium, CO from a stepped platinum surface, and N2from rhodium, respectively (data adapted from [J.W. Niemantsverdriet,...

A variety of model catalysts have been employed we start with the simplest. Single-crystal surfaces of noble metals (platinum, rhodium, palladium, etc.) or oxides are structurally the best defined and the most homogeneous substrates, and the structural definition is beneficial both to experimentalists and theorists. Low-energy electron diffraction (LEED) facilitated the discovery of the relaxation and reconstruction of clean surfaces and the formation of ordered overlayers of adsorbed molecules (3,28-32). The combined application of LEED, Auger electron spectroscopy (AES), temperature-programmed desorption (TPD), field emission microscopy (FEM), X-ray and UV-photoelectron spectroscopy (XPS, UPS), IR reflection... 

Figure 1 Schematic of the experimental UHV/electrochemical transfer system used for studies on modified platinum single-crystal surfaces. (From Ref. 26.) The UHV system has facilities for X-ray photoelectron spectroscopy (XPS), low-energy ion scattering spectroscopy (LEISS), low-energy electron diffraction (FEED), and temperature-programmed desorption (TPS). The electrochemical chamber allows the electrochemical cell, 0 with integral counter, reference, and secondary working electrode, to be brought to the surface allowing contact of the electrolyte with the transferred surface.

Aben, P.C. van der Eijk, H. and Oelderik, J.M. "The characterization of the metal surface of alumina-supported platinum catalysts by temperature-programmed desorption of chemisorbed hydrogen." In Hightower, J.W., ed. Proceedings of the Fifth International Congress on Catalysis. Vol. 1. Amsterdam North-Holland 1973 p. 717-726. 

Temperature programmed desorption (TPD) and temperature programmed reduction (TPR) are popular for characterizing platinum-based catalysts for fuel cell applications, especially the TPR technique. Usually some thermodynamic and kinetic parameters of gas/solid desorption processes and decomposition reactions on surfaces involving gaseous products can be quantitatively measured by TPD, and promotion of additives can be investigated by TPR. 

Lamouri A, Gofer Y, Luo Y, Chottiner GS, Scherson DA. Low energy electron diffraction. X-ray photoelectron spectroscopy, and CO-temperature-programmed desorption characterization of bimetallic mtheninm-platinum surfaces prepared by chemical vapor deposition. J Phys Chem B 2001 105 6172-7. 

The rate of the elementary reaction between Oads and COads to CO2 can be determined separately by coadsorbing CO and O2 on a metal surface and studying the rate of CO2 formation in the gas phase using temperature programmed desorption spectroscopy. According to Zhdanov (1991b), typical values of the preexponential and activation energy are 10 /s and 45 kJ/mol for the reaction on platinum... 

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