新型Pd／HZSM-5-N催化剂的制备及其在苯甲醇氧化反应中的应用

摘要

以分子筛HZSM-5为前驱体，氨气为氮源，直接高温氮化制得掺氮分子筛HZSM-5-N（1）；以Pd（OAc）2为钯源，1为载体，采用溶胶-固载法制备了一系列不同钯负载量（α）的新型Pdα／1催化剂，其结构和性质经SEM， FT-IR，元素分析，XRD， N2-BET和ICP表征。以苯甲醇氧化成苯甲醛反应为探针反应，研究了α， Pdα／1用量，反应时间和反应温度对Pdα／1催化性能的影响。结果表明：在最优反应条件（ Pd2／140 mg，于120℃反应180 min）下，苯甲醇转化率为66．7％，苯甲醛选择性为92．9％。 Pd2／1重复使用性能较好，循环使用5次，催化活性保持不变。%The doped nitrogen molecular sieve, HZSM-5-N(1), was obtained by directly high temper-ature nitridation , using molecular sieve HZSM-5 as precursor and ammonia as nitrogen source .A series of catalysts(Pdα/1) with different Pa loading(α) were prepared by sol-immobilization method, using 1 as supporter and Pd ( OAc) 2 as Pd source .The structures and properties of Pdα/1 were characterized by SEM, FT-IR, elemental analysis, XRD, N2-BET and ICP.Effects of α, Pdα/1 dosage, reaction time and temperature on catalytic performances of Pd α/1 were investgated , using benzyl alcohol oxida-tion as the template reaction .The results showed that conversion of benzyl alcohol was 66 .7%and se-lectivity of benzaldehyde was 92.9%under the optimum reaction conditions (Pd2/1 40 mg, reacted at 120 ℃for 180 min) .The catalytic performance of Pd 2/1 remain stable after recycling for five times .