Service Detail from Quantachrome Instruments
In contrast to physisorption, chemical adsorption (chemisorption) involves the formation of strong bonds between adsorbate molecules and specific surface locations known as active sites. Chemisorption is used primarily to evaluate the number of surface active sites which are likely to promote (catalyze) chemical reactions. Related temperature programmed (i.e. non-isothermal) methods such as TPR, TPO and TPD are used to determine relative ease of reduction (of oxides), oxidation (of low valency species, particularly carbons) and desorption (of ammonia from acid sites for example). Activation energy for a given chemical process can be gleaned by employing different heating rates.