Temperature-programmed desorption results

There are also a few papers reporting results on the hydrogen desorption of the ball-milled mixtures of MgH and carbon/graphite studied by temperature programmed desorption (TPD), DSC, and TGA [145-147], However, they do not report any particularly exciting results that would warrant a more thorough discussion. 

The temperature programmed desorption profile for the adsorption of butadiene in place of cis-2-butene is shown in Fig. 1, curve c. Two sets of products are observed. The product below 210°C is unreacted butadiene, and the products above 210°C are carbon dioxide and water. The similarity in the evolution of the combustion products of butene and butadiene is an indication that their combustion proceeds via similar reaction mechanisms. The similarity in the desorption of butadiene suggests that in butene adsorption, butadiene desorption is desorption limited. Indeed, that both butene and butadiene adsorb on the same type of sites has been confirmed by sequential adsorption experiments. The results are shown in Table III. It was found that if the C4 hydrocarbons are adsorbed sequentially without thermal desorption between adsorptions, the amounts of the final desorption products are the same as those in experiments where only the first hydrocarbon... 

Results of temperature-programmed desorption (TPD) of ammonia125 or argon126 were attributed to superacid sites. TPD of very weak bases such as substituted benzenes has been used successfully to compare the superacid character of a series... 

Additional strong evidence for electronic effects in bimetallic systems comes from the recent work of Goodman and coworkers.(7) Employing temperature programmed desorption (TPD) and XPS, it was shown that CO adsorption to thin layers of Pd on Ta or W crystals was significantly altered by the Ta or W crystalline substrate. It was found that XPS (Pd(3d 5/2)) core level shifts correlated with the changes in CO adsorption strength. Similar results have been observed with Cu on Rh crystals. 

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