Sulfur poisoning, recovery and related phenomena over supported palladium, rhodium and iridium catalysts for methane oxidation

Methane catalytic combustion over Pd/Al2O3 in presence of sulphur dioxide: development of a deactivation model

“…This author considers very interesting the development of mechanistic models, which consider the phenomena taking place on the catalyst. The sulphur poisoning of Pd catalysts in deep oxidation reactions has been shown to be caused by the formation of surface Pd sulphates [9][10][11]20,24]. So, as time on stream increases, Pd sulphate is progressively formed, and the concentration of the most active Pd phase (oxide), and hence the catalytic activity, decreases.…”

“…Sulphur deactivation in Pd catalysts has been studied in the literature in oxidation and in hydrogenation reactions. Deng et al [20] studied the sulphur poisoning for the oxidation of 1% vol. methane in air at temperatures between 350 and 600 • C, adding hydrogen sulphide pulses of up to 200 ppm.…”

Poisoning effect of thiophene on the catalytic activity of molybdenum carbide during tri-methyl pentane reforming for hydrogen generation

“…While these fuels are rich in hydrogen, they also contain sulfur compounds as well as coke precursors. Unfortunately, the typical metal reforming catalysts are prone to deactivation by coking, as well as sulfur poisoning [3][4][5]. Whereas coking can be controlled with excess steam (and/or oxygen injection), the high sulfur levels in these fuels will require sulfur removal upstream of the reformer [6], if conventional reforming catalysts are employed.…”

Electrochemical promotion of CH4 oxidation on Pd

“…The dependence of the catalytic activity for methane combustion on the chemical state of palladium is quite complex [11]. Many studies have appeared in literature concerning the kinetics of the reaction [12,13], the effect of support [14 -16], poisoning [17,18], aging of catalyst [19], initial induction period for activation [15,20] and the relation of the activity of the catalyst to its oxidative state [12,21]. It is generally accepted that deep oxidation of methane on Pd under oxygen-rich conditions is a structure sensitive reaction [22].…”