通过浸渍法制备了ZnO/NaY催化剂,采用XRD、BET、异丙醇探针反应等手段对其物化性质进行了表征,并考察了催化剂对尿素和1,2-丙二醇在固定床反应器上减压条件下合成碳酸丙烯酯的催化性能。结果表明:负载适量的ZnO没有改变NaY分子筛的骨架结构,且ZnO高度分散于NaY分子筛表面。当ZnO质量分数为5%时,催化剂表现出较好的催化活性,尿素的转化率和碳酸丙烯酯的收率分别达到86.2%和82.3%.N2气氛下异丙醇探针反应结果表明,催化剂表面的酸性位与碱性位分布直接影响催化剂催化活性。
ZnO/NaY catalysts were prepared by the impregnation method and their physical chemical properties were characterized by XRD, BET and isopropanol (IPA) probe reaction. It was revealed that ZnO was well dispersed on the surface of NaY when the ZnO content was less than mass ratio 5% from the XRD patterns. The results of IPA probe reaction indicated that the doped ZnO affected the distribution of acidity and basicity of the catalysts. The synthesis of propylene carbonate (PC) from propylene glycol (PG) and urea was carried out in a fixed bed reactor with ZnO/NaY catalysts, Compared with pure ZnO or NaY, ZnO/NaY catalyst containing the mass ratio of 5% ZnO showed high activity toward the reaction. Urea conversion was 86. 2% and the yield to PC reached 82.3%.