A simple method for CO chemisorption studies under continuous flow: Adsorption and desorption behavior of Pt/Al2O3 catalysts

A simple and rapid method for the determination of metal dispersion of technical catalysts is presented, which is based on temperature-programmed desorption (TPD) of pre-adsorbed CO in a continuous-flow reactor at atmospheric conditions. A commercial Pt/Al2O3 diesel oxidation catalyst is studied as an example. In the TPD spectra, desorption of CO as well as CO2 is considered. Furthermore, a pulse adsorption technique is applied to better understand the adsorption–desorption behavior and the oxidation of CO. Metal dispersion based on the TPD methods presented agrees well with data derived from H2 and CO chemisorption measurements using commercial set-ups.

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► A simple and rapid method for determination of metal dispersion is presented.
► Pt/Al2O3 is studied based on a CO TPD method at atmospheric pressure.
► CO2 found in TPD is attributed to CO oxidation by O2 in the carrier gas.
► Dispersion agrees with data from a pulse adsorption technique and commercial devices.