【摘 要】
：
A series of nanocrystalline γ-alumina are synthesized by different procedures, namely, thermal decomposition method (sample A), precipitation method (sample B)
【机 构】
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Catalyst and Advanced Materials Research Laboratory,Institute of Nanoscience and Nanotechnology,Cata
论文部分内容阅读
A series of nanocrystalline γ-alumina are synthesized by different procedures, namely, thermal decomposition method (sample A), precipitation method (sample B) and sol-gel method using sucrose and hexadecyltrimethyl ammonium bromide (CTAB) as templates (samples C and D, respectively). Textural and acidic properties of γ-alumina samples are characterized by XRD, N2 adsorption-desorption and NH3-TPD techniques. Vapor-phase dehydration of methanol into dimethyl ether is carried out over these samples. Among them, sample C shows the highest catalytic activity. NH3-TPD analysis reveals that the sample with smaller crystallite size possesses higher concentration of medium acidic sites and consequently higher catalytic activity. Thermal decomposition method leads to decrease in both surface area and moderate acidity, therefore it is the cause of lower catalytic activity.
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