Pb掺杂改性对Pt/HZSM-5催化剂结构及其催化合成对氨基苯酚反应性能的影响  

Effect of Pb Doping on the Structure of Pt/HZSM-5 and Its Catalytic Performance in p-Aminophenol Synthesis

作　　者：何蓓蓓[1] 王淑芳[1] 王延吉[1] 赵新强[1] 

机构地区：[1]河北工业大学绿色化工与高效节能河北省重点实验室,天津300130

出　　处：《石油学报（石油加工）》2013年第1期51-55,共5页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：国家重大基础研究前期专项(2010CB234602);国家自然科学基金(20876033);河北省自然科学基金(B2011202197)项目资助

摘　　要：针对硝基苯催化加氢合成对氨基苯酚(PAP)反应,以HZSM-5(n(SiO2)/n(Al2O3)=25)为载体,制备了不同Pt负载量的Pt/HZSM-5及Pb-Pt/HZSM-5双功能催化剂,采用透射电镜(TEM)、氢气程序升温脱附(H2-TPD)、CO吸附漫反射红外光谱(DRFTIR)和X射线光电子能谱(XPS)技术对催化剂结构和电子性能进行了表征,同时评价了催化剂催化合成PAP的活性。结果表明,Pb的掺杂改性能有效提高Pt在载体表面的分散度,改性后催化剂Pt的电子密度增大。Pb-Pt/HZSM-5催化剂催化合成PAP的选择性明显高于相同负载量下的Pt/HZSM-5催化剂。由于Pb、Pt之间相互作用导致的Pt活性位上电子密度的增大对苯基羟胺(PHA)连串加氢生成苯胺反应起到了明显的抑制作用。A series of HZSM-5-supported Pt and Pb-Pt catalysts of various Pt loading（Pt/HZSM-5, Pb-Pt/HZSM-5） were prepared for the hydrogenation of nitrobenzene （NB） to p-aminophenol （PAP）. The structural modification and change in electronic properties of the catalysts were analyzed by using high-resolution transmission electron microscopy, temperature-programmed desorption of hydrogen, diffuse reflectance infrared Fourier transformation spectroscopy of the adsorbed carbon monoxide and X-ray photoelectron spectroscopy analysis. The catalytic performances of Pt/HZSM-5, Pb-Pt/HZSM-5 in PAP synthesis were evaluated. The Results revealed that Pb doping in the Pt/HZSM-5 catalysts improved the dispersion of Pt species and increased electron density of Pt. The PAP selectivity over Pb-Pt/HZSM-5 was obviously higher than that over Pt/HZSM-5 with the same Pt loading. The increased electron density of Pt caused by the interaction of Pb and Pt played a positive role to inhibit the subsequent hydrogenation of PHA to aniline.

关 键 词：对氨基苯酚 硝基苯 催化加氢 双功能催化剂 

分 类 号：TQ032.41[化学工程]