CAJ | 학술논문

制备了表面修饰多壁碳纳米管负载TiO2的催化剂，并将其应用于碳酸二甲酯与苯酚的酯交换反应.采用X射线电子能谱、透射电子显微镜、低温N2吸附-脱附和X射线衍射等对催化剂进行了表征.结果表明，以低浓度的氨水(0.4%)代替去离子水作为沉淀剂时，制备的催化剂显示出更好的催化活性、分离性与重复使用性.考察了TiO2负载量、催化剂用量及反应时间对反应性能的影响.在最佳反应条件下，苯酚转化率为42.5%，碳酸甲苯酯与碳酸二苯酯的总选择性达到99.9%以上.经过4次重复使用后，催化剂的活性略有下降.
제비료표면수식다벽탄납미관부재TiO2적최화제，병장기응용우탄산이갑지여분분적지교환반응.채용X사선전자능보、투사전자현미경、저온N2흡부-탈부화X사선연사등대최화제진행료표정.결과표명，이저농도적안수(0.4%)대체거리자수작위침정제시，제비적최화제현시출경호적최화활성、분리성여중복사용성.고찰료TiO2부재량、최화제용량급반응시간대반응성능적영향.재최가반응조건하，분분전화솔위42.5%，탄산갑분지여탄산이분지적총선택성체도99.9%이상.경과4차중복사용후，최화제적활성략유하강.
Modified multi-walled carbon nanotube-supported TiO2 samples were prepared and used as an efficient heterogeneous catalyst for the transesterification of dimethyl carbonate with phenol. The catalysts were characterized by X-ray photoelectron spectroscopy, transmission electron micros-copy, N2 adsorption-desorption, and X-ray powder diffraction. The results showed that the catalyst, which was prepared using a low concentration (0.4%) of ammonium hydroxide as the precipitant instead of ionized water, had better catalytic activity, separability, and reusability properties. The effects of the TiO2 loading, amount of catalyst and reaction time on the performance of the trans-esterification reaction were also studied. Under the optimum reaction conditions, the conversion of phenol reached 42.5% with over 99.9% selectivity for methyl phenyl carbonate and diphenyl car-bonate. The catalyst could be reused for the transesterification in four runs with only slight loss of its catalytic activity.