Adsorption effects during temperature-programmed desorption of carbon monoxide from supported platinum

摘要: Experimental data are presented for the temperature-programmed desorption (TPD) of CO from porous PtAl2O3 into a vacuum. Most preadsorbed desorbs in peak between 380 and 550 K. Other workers have measured at substantially higher temperatures during TPD carrier gas rather than A comparison experimental conditions suggests that competition adsorption with may contribute to differences results. To investigate effects adsorption, we develop mathematical model use it compute spectra Pt dispersed over support (a) an inert (b) Over realistic parameter range considered, our predicts effects, caused by high concentrations gaseous system, always important feature, broadening peaks shifting them temperatures. Indeed, find competes extent equilibrium is approached closely within supported samples. For gas, result limitations flow sample cell, whereas vacuum, diffusion sample. Our results suggest significant will also be present other Group VIII precious metals supports.