CAJ | 학술논문

采用共沉淀法,以氨水为沉淀剂制备了一系列具有不同Mg/Al摩尔比的镁铝氧化物催化剂,考察了它们在丙酮气相缩合反应中的催化性能,并通过XRD,SPS,ICP,TG-DTA和TPD等手段对催化剂的结构和性质进行了表征.实验结果表明,以反滴沉淀方式制备的Mg_(1.0) AlO催化剂具有较高的反应活性和稳定性,在反应温度为573 K条件下,反应85 h后丙酮的转化率仍可以达到65%.镁铝氧化物表面存在一定量强度和密度相互匹配的弱碱和强碱中心对提高催化剂的活性和稳定性有利.
채용공침정법,이안수위침정제제비료일계렬구유불동Mg/Al마이비적미려양화물최화제,고찰료타문재병동기상축합반응중적최화성능,병통과XRD,SPS,ICP,TG-DTA화TPD등수단대최화제적결구화성질진행료표정.실험결과표명,이반적침정방식제비적Mg_(1.0) AlO최화제구유교고적반응활성화은정성,재반응온도위573 K조건하,반응85 h후병동적전화솔잉가이체도65%.미려양화물표면존재일정량강도화밀도상호필배적약감화강감중심대제고최화제적활성화은정성유리.
Mg-Al oxide catalysts were prepared by co-precipitation method, used ammonia as the precipitating agent. The catalytic performances of these materials were investigated in the gas-phase Aldol condensation of acetone to isophorone. The structure and surface properties of the catalysts were characterized by means of XRD, XPS, ICP, TG-DTA and TPD. The Mg_(1.0)AlO catalyst prepared by back-titration shows relatively high activity and stability, the conversion of acetone maintains at 65% even after 85 h at 573 K. The co-existence of a certain amount of weak basic centers and strong basic centers on the surface Mg-Al oxides may play an important role for improving the activity and stability of these catalysts.