Deactivation of titanium during temperature-induced hydrogen absorption–desorption cycling

Deactivation of titanium during temperature-induced hydrogen absorption–desorption cycling

“…3b, Table 1). The value of hydrogen absorbed according to TPD data is 1.36 wt%, which corresponds to H 2 absorption in H 2 /Ar or He flows reported in previous paper [9]. During the second absorption--desorption cycle, propane pyrolysis dominates and hydrogen absorption is masked by hydrogen evolution (Fig.…”

“…(ii) Water is not formed in the presence of titanium. On the contrary, it is consumed due to reaction with it, as was similarly observed in TPR runs carried out in He and Ar flows [9].…”

“…4, Table 1). As in the case of experiments in inert gases [9], oxygen, water and, most probably, nitrogen promote deactivation of titanium. Thus, a 2-3-fold increase in oxygen concentration leads to a 1.5-2-fold drop in hydrogen absorption.…”

“…[7,8]. Even at concentrations lower than 1% for such typical impurities as O 2 , H 2 O and N 2 , complete deactivation of titanium in only one TPR-TPD cycle is experienced [9]. Evidently, during the dehydrogenation reaction, the concentration of organic material may be rather high, thus making the probability of deactivation quite high.…”

Kinetics of thermal decomposition of titanium hydride powder using in situ high-temperature X-ray diffraction (HTXRD)

“…The latter might strongly affect the kinetics of hydrogen desorption, even when interstitials are present in very low contents 15 . This aspect is relevant since titanium is a reactive metal; however, oil-free dynamic vacuum conditions were established in our experiments minimizing carbon pick-up at least.…”