摘要
采用FT-IR、XRD、BET、NH3-TPD、NH3吸附红外和TG等表征低温陈化法制备的固体超强酸SO42-/SnO2和SO42-/SnO2-Al2O3,考察Al的引入对SO42-/SnO2表面结构、晶体结构、比表面积、酸量、酸性位和热稳定性的影响。结果表明:Al的引入会阻止SnO2晶化,减小催化剂的晶粒尺寸,增大了催化剂的比表面积;增加了固体超强酸表面B酸、L酸强度和酸总量;提高SnO2表面结合SO42-的能力。将SO42-/SnO2和SO42-/SnO2-Al2O3分别应用于乙二醇丁醚乙酸酯(BGA)的合成,重复使用6次后,BGA收率分别为58.9%和81.2%,表明Al的引入显著延长了催化剂的寿命。
The solid superacid catalysts SO42 /SnO2 and SO42 /SnO2-Al2O3 were prepared by the method of aging at low temperature.The influences of introduction of aluminum on the surface structure,crystallite structure,specific areas,acidity,types of acid site and the thermal stability of the prepared catalysts were investigated by the means of Fourier transform infrared（FT-IR）,powder X-ray diffraction（XRD）,BET surface area analysis（BET）,temperature-programmed desorption of ammonia（NH3-TPD）,infrared spectra of adsorbed ammonia（NH3-IR） and thermogravimetry（TG）,respectively.The results show that the introduction of aluminum inhibits the growth of SnO2 crystallites,decreases the crystallite size and promotes higher specific areas of the catalyst.Comparing with SO42-/SnO2,in SO42-/SnO2-Al2O3 the intensity of attached-on-surface sulfuric groups is increased,the amount of effective acid is enhanced and the strengths of Brnsted and Lewis acid sites are improved.The TG results reveal that the aluminum could improve the sulphate binding capacity of SnO2 surface.When SO42-/SnO2 and SO42-/SnO2-Al2O3 were used separately as catalyst to synthesis butyl glycol acetate（BGA）,after the catalysts were used for six times,the yields of BGA are 58.9% and 81.2%,respectively;thus indicating that the introduction of aluminum obviously prolongs the catalytic life of the SO42 /SnO2 type solid superacid catalyst.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2011年第2期259-263,共5页
Journal of Chemical Engineering of Chinese Universities
关键词
低温陈化
固体超强酸
氧化锡
氧化铝
表征
aging at low temperature
solid superacid
tin dioxide
alumina
characterization
