CONTROLLED-RATE THERMAL-DESORPTION

A new way of conducting thermal desorption experiments is described. T he method consists in maintaining the desorption rate constant by a ri gorous control of temperature. The equations for two models of constan t rate desorption are described: from a surface with only one type of adsorption site, and with two different types. The technique is applie d to two real systems and the kinetic parameters are determined. The r esults are compared with those obtained by using TPD. The main advanta ges are discussed and the methodology and modifications required for a TPD set-up to work at a constant desorption rate are described.