“…It must be remembered that all catalysts had a tungsten content of 2.8 W atoms/nm 2 and that the surface areas of the rich titanium samples (x = 0.95 and 1.0) are quite low compared to the other catalyst samples with less titanium. Also, in the study of TPR profiles of different catalysts it is not advisable to change the size of the sample since, as has been demonstrated before (40), the TPR results from samples of different size may not be comparable. However, in this sample (W/Al-Ti(1.0)), a small hydrogen consumption due to the reduction of the anatase present in the support was detected at about 893 K. Another even smaller hydrogen consumption peak, most probably due to the reduction of W 6+ species appeared at about 1053 K and the beginning of the high reduction temperature peak, consistent with the reduction of rutile started to appear above 1173 K.…”