摘要
采用水解与超声相结合的方法制备了催化剂二氧化钛,用于碳酸二甲酯与苯酚酯交换合成碳酸二苯酯的反应,并用XRD和FT-IR对催化剂进行了表征。焙烧温度在130℃时,二氧化钛以无定形态存在;200℃开始出现锐钛矿二氧化钛,随温度的升高,钛逐渐由四面体配位向八面体配位转变。活性随焙烧温度升高而降低,200℃时活性较好,苯酚转化率可达33.7%,未检测到副产物;温度为400℃催化剂几乎没有活性,表明晶相二氧化钛的形成不利于苯酚与碳酸二甲酯的酯交换。
TiO2 catalyst was prepared by hydrolysis combined with ultrasonic and used in the synthesis of diphenyl carbonate by transesterification of dimethyl carbonate and phenol.The catalysts were characterized by X-ray diffraction and FT-IR spectroscopy.The result shows that amorphous TiO2 with tetrahedral symmetry exists over the catalyst calcined at 130 ℃;from 200 ℃,anatase TiO2 is detected and Ti symmetry gradually turns from tetrahedral symmetry to octahedral symmetry.The catalytic activity decreases with the increasing of calcined temperature,and the conversion of phenol and the transesterification selectivity over the TiO2 catalyst which was calcined at 200 ℃ are 33.7% and 99.9%,respectively.TiO2 calcined at 400 ℃ is essentially inactive for this reaction.The result indicates that anatase TiO2 is disadvantage of transesterification between phenol and dimethyl carbonate.
出处
《化学工程》
CAS
CSCD
北大核心
2011年第11期61-65,共5页
Chemical Engineering(China)
基金
中国科学院2007"西部之光"联合学者项目
关键词
二氧化钛
碳酸二苯酯
碳酸二甲酯
酯交换
四面体配位
TiO2
diphenyl carbonate
dimethyl carbonate
transesterification
tetrahedral symmetry
