摘要
研究了γ Al2O3经过较低温度的水热处理后的晶型变化情况。XRD、SEM和FT IR表征结果表明,影响γ Al2O3再水合产物晶型的主要因素是水热温度。100℃以下水热处理的产物是湃铝石,100～110℃水合产物是湃铝石和薄水铝石的混合物,110℃以上水热处理的产物是薄水铝石,且不经过湃铝石的中间阶段。随着水合温度升高,薄水铝石的结晶度增大。在保证充分润湿的前提下,水合产物的结晶度和晶粒度与水铝质量比无关。
The rehydration of γ-Al_2O_3, obtained by dehydration of pseudoboehmite, at lower temperature was investigated. The influence of hydrothermal reaction temperature and H_2O/γ-Al_2O_3 mass ratio on crystallinity and crystal size of the rehydrates were examined by means of XRD, SEM and FT-IR. It is found that, when γ-Al_2O_3 was sufficiently moistened, crystallinity and crystal size of the rehydrates formed were dependent on rehydration temperature rather than H_2O/γ-Al_2O_3 mass ratio. At lower temperature, bayerite was the only rehydrate formed. At higher temperature, the rehydration of γ-Al_2O_3 gave rise to the formation boehmite. The higher the rehydration temperature, the higher relative crystallinity of the rehydrates.
出处
《工业催化》
CAS
2004年第10期44-48,共5页
Industrial Catalysis
