INFRARED STUDY OF MOLECULARLY ADSORBED H2 ON ZRO2

Molecularly adsorbed dihydrogen (H-H) species were observed on ZrO2 by Fourier-transform infrared (FT-IR) spectroscopy in the temperature range of 85-300 K. The IR spectra show that there are three types of H-2(a) species giving absorption bands al 4054, 4031 and 3996 cm-1. In case of HD and D2, these bands shift to 3539, 3518 and 3485 cm-1, and 2914, 2897 and 2866 cm-1, respectively. The nature of these three species differ from one another. It is also found that the species which gives the band at 4029 cm-1 is the most stable adsorbate and that this species shares the same adsorption site with the ZrH and OH species resulting from the heterolytic dissociative adsorption of H-2 on the Zr-O pair site.