期刊名称:Chemical Industry and Chemical Engineering Quarterly
印刷版ISSN:1451-9372
出版年度:2012
卷号:18
期号:2
页码:209-220
DOI:10.2298/CICEQ110602062S
出版社:Association of the Chemical Engineers
摘要:Two series of zirconia based catalysts promoted with either sulfates or phosphates were prepared, calcined at different temperatures (600 and 700°C) and evaluated for the n-hexane isomerization reaction. The catalysts with different concentrations of sulfates or phosphates (4 or 10 wt. %) were characterized by BET, XRD, SEM methods, and total acidity was evaluated by using the Hammett indicators. Their final catalytic performances were correlated with their physical-chemical properties (surface, structural, textural and morphological). It was found that sulfated zirconia catalyst calcined at lower temperature showed the highest initial activity of all tested catalysts as the result of favorable total acidity, mesopore texture and structural properties. Somewhat lower activity of the sulfated catalyst calcined at higher temperature is related to the content of acid groups partially removed during thermal treatment, thus, lower total acidity, and also to less favorable textural and structural features. Negligible activity of phosphated zirconia catalysts is connected with low total acidity despite the positive status of particular property showing the complexity of the active phase/site formation in the catalyst.
关键词:catalyst; isomerization of n-hexane; phosphated zirconia; sulfated zirconia