Surface chemistry temperature-programmed desorption

Finally, although both temperature-programmed desorption and reaction are indispensable techniques in catalysis and surface chemistry, they do have limitations. First, TPD experiments are not performed at equilibrium, since the temperature increases constantly. Secondly, the kinetic parameters change during TPD, due to changes in both temperature and coverage. Thirdly, temperature-dependent surface processes such as diffusion or surface reconstruction may accompany desorption and exert an influence. Hence, the technique should be used judiciously and the derived kinetic data should be treated with care ... 

The surface chemistry of carborane (C2B10H12) and decaborane (B10H14) on Pt(lll) has been studied with reflection absorption infrared spectroscopy (RAIRS), temperature programmed desorption (TPD), and X-ray photoelectron spectroscopy (XPS). It is found that the Pt surface catalyzes the release of hydrogen from both molecules at temperatures much lower than their thermal decomposition temperatures. The thermal degradation of these two molecules was found to occur in stages as shown by the TPD results. From XPS data, it was concluded that boron remains on the surface up to very high temperatures. 

The TiO2(110) surface can be modified to alter the surface chemistry of adsorbed methoxides. Recently Vohs et al. [73] have reported temperature programmed desorption studies of methanol on TiO2(110)-supported V2O5. Deposited monolayer films of vanadia converted some of the adsorbed methanol to formaldehyde and water, while multilayer films of vanadia on the TiO2(110) surface were found to be inactive for methanol oxidation. Furthermore, adsorption studies of formaldehyde indicated that formaldehyde production from... 

Surface-enhanced Raman scattering detected temperature programmed desorption optical properties, nanostructure, and stability of silver film over SiO2 nanosphere. Journal of Physical Chemistry B, 105, 6907-6915. 

Temperature programmed desorption (TPD), also called thermal desorption spectroscopy (TDS), provides information about the surface chemistry such as surface coverage and the activation energy for desorption... 

As a complement to acid-base titration, temperature-programmed desorption (TPD) has become a rather popular method over the last decade, in an attempt to identify the oxygenated groups either in raw materials or after their oxidation [11,25,54,73-77]. It has been applied mainly to active carbons of various origins (Table 3.1) as these materials are well known to have a surface chemistry with high contents of oxygenated species. 

Thermal desorption spectroscopy and temperature programmed reaction experiments have provided significant insight into the chemistry of a wide variety of reactions on well characterized surfaces. In such experiments, characterized, adsorbate covered, surfaces are heated at rates of 10-100 K/sec and molecular species which desorb are monitored by mass spectrometry. Typically, several masses are monitored in each experiment by computer multiplexing techniques. Often, in such experiments, the species desorbed are the result of a surface reaction during the temperature ramp. 

R.J. Madix. The Application of Flash Desorption Spectroscopy to Chemical Reactions on Surfaces Temperature Programmed Reaction Spectroscopy. In R. Vanselow, editor, Chemistry and Physics of Solid Surfaces, Volume 2. CRC Press, Boca Raton, FL, 1979. 

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