화학공학소재연구정보센터
Materials Research Bulletin, Vol.65, 279-286, 2015
(Al1-xCrx)(4)B6O15 (0.08 <= x <= 0.14): Metal borates catalyze the dehydration of methanol into dimethyl ether
PKU-5 (Al4E6O15) is potentially a solid acid catalyst, and it possesses an interesting open-framework composed of [AlO6] and [B2O5] groups. PKU-5 shows a high thermal stability, while no physical and chemical properties were investigated thus far, because of the difficulty in its synthesis. Cr-stabilized PKU-5 with the formula (Al1-xCrx)(4)B6O15 (0.08 <= x <= 0.14) can be easily prepared by annealing Cr-doped PKU-1 precursors. XRD and TEM experiments demonstrate Cr3+ has been successively incorporated into the framework of PKU-5. NH3-TPD measurements indicate that the partial substitution of Al3+ by Cr3+ leads to a small change of acid sites in total amounts and distributions. Cr-PKU-5 shows a good catalytic activity for methanol dehydration from 300 to 450 degrees C. Other operation conditions, such as the Cr3+ content, space velocity of methanol were also discussed in detail to evaluate its catalytic performance. (C) 2015 Elsevier Ltd. All rights reserved.