Pd/SiC催化苯甲醛加氢反应性能  

Catalytic performance of Pd/SiC for benzaldehyde hydrogenation

作　　者：吉晓云 焦志锋 赵吉晓 李佳航 郭向云 JI Xiaoyun;JIAO Zhifeng;ZHAO Jixiao;LI Jiahang;GUO Xiangyun(Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology,School of Petrochemical Engineering,Changzhou University,Changzhou 213164,Jiangsu,China)

机构地区：[1]常州大学石油化工学院,江苏省绿色催化材料与技术重点实验室,江苏常州213164

出　　处：《精细化工》2025年第3期594-602,共9页Fine Chemicals

基　　金：江苏省高等学校基础科学(自然科学)研究面上项目(22KJB150017)。

摘　　要：以高比表面积(约30 m^(2)/g)SiC为载体,采用液相还原法制备了负载型催化剂Pd/SiC。通过TEM、XRD、XPS对其进行了表征。考察了Pd理论负载量(简称Pd负载量)、载体类型、反应溶剂和反应H_(2)压力对其催化苯甲醛加氢合成苯甲醇反应的影响。采用原位漫反射红外光谱仪探究了反应机理,并考察了催化剂的循环稳定性。结果表明,Pd负载量(质量分数)1%的Pd_(1)/SiC的催化活性优于相同Pd负载量的不同载体催化剂Pd_(1)/SiO_(2)、Pd_(1)/Al_(2)O_(3)和Pd_(1)/TiO_(2)的催化性能,在以无水乙醇为溶剂、反应温度60℃、反应H_(2)压力0.5 MPa的条件下,30 mg的Pd_(1)/SiC催化1 mmol苯甲醛加氢反应30 min时,苯甲醛转化率为100.0%,苯甲醇选择性>99.0%。Pd/SiC催化苯甲醛加氢生成苯甲醇的反应机理可能为:金属Pd解离H_(2),SiC表面吸附并活化苯甲醛分子,活性氢在Pd表面形成后溢流到SiC表面与活化了的苯甲醛发生反应,形成苯甲醇。Pd_(1)/SiC循环使用5次后,苯甲醛转化率为93.0%;Pd_(1)/SiC中Pd纳米颗粒在SiC表面分散较好,平均粒径为4.8 nm,载体SiC和Pd之间明显存在电子转移。Supported catalyst Pd/SiC was prepared by liquid phase reduction method using high specific surface area(about 30 m^(2)/g)SiC as carrier,and characterized by TEM,XRD and XPS.The effects of Pd theoretical loading(for short Pd loading),carrier type,reaction solvent and reaction H_(2)pressure on the catalytic hydrogenation of benzaldehyde to benzyl alcohol were evaluated.The catalyst obtained was also analyzed for its reaction mechanism via in-situ diffuse reflection infrared spectroscopy and its cyclic stability.The results showed that Pd_(1)/SiC with 1%Pd loading(mass fraction)displayed better catalytic performance than Pd_(1)/SiO_(2),Pd_(1)/Al_(2)O_(3)and Pd_(1)/TiO_(2)with the same Pd loading.Under the conditions of 30 mg Pd_(1)/SiC and anhydrous ethanol as catalyst and solvent,temperature 60℃,reaction H_(2)pressure 0.5 MPa and time 30 min,the 1 mmol benzaldehyde conversion reached 100.0%,while the phenyl methanol selectivity was greater than 99.0%.The Pd/SiC catalytic mechanism on hydrogenation of benzaldehyde to benzyl alcohol might be attributed to the reaction of H_(2)dissociated by metal Pd and overflowed to SiC surface and benzaldehyde molecules adsorbed and activated by SiC surface.After Pd_(1)/SiC being recycled for 5 times,the conversion rate of benzaldehyde was 93.0%.Pd nanoparticles in Pd_(1)/SiC were well dispersed on the surface of SiC with an average particle size of 4.8 nm,and there was obvious electron transfer between the carrier SiC and Pd.

关 键 词：Pd/SiC 苯甲醛加氢 负载型SiC基催化剂 催化加氢 氢溢流 

分 类 号：TQ426.8[化学工程]