载体疏水结构对Pt/疏水陶瓷催化剂性能影响研究

为验证疏水结构对催化剂性能的影响规律，研究以柱状（φ=5 mm）多孔陶瓷为载体，在载体表层构筑三种不同的氧化铈（CeO₂）微纳结构为载体提供疏水环境，通过浸渍-气相还原法制得用于氢同位素分离的Pt/疏水陶瓷催化剂，以X射线衍射（XRD）、扫描电镜（SEM）、能谱（EDX）、X光电子能谱（XPS）及一氧化碳（CO）脉冲吸附等对催化剂性能进行综合表征，并采用气汽并流方式测试催化剂催化活性。结果表明，不同疏水结构对载体孔结构及零价铂含量影响可忽略不计，对铂粒子在载体表层的富集程度及催化剂铂粒子分散度影响明显，制得的催化剂催化活性差距明显。分布均匀且对载体覆盖率高的绒毛状疏水结构可使得更多的铂粒子沉积在载体表层，可获得更优的催化活性。

The Influence of Hydrophobic Structure on the Performanceof Pt/Ceramic Hydrophobic Catalyst

This research adopted column porous ceramics(φ=5 mm)as the carriers,the hydrophobic carriers with three different kinds of nanostructured cerium oxide(CeO 2)coating were fabricated and then catalysts which were used in hydrogen isotope separation were manufactured by convenient impregnation method,and the catalytic activity were tested through catalytic exchange reaction between hydrogen and saturated water vapor.The samples were characterized by XRD,SEM,EDX,XPS and CO adsorption to verify the influence of hydrophobic structure on the properties of catalyst.The results showed that the hydrophobic nanostructure made no influence on the pore structure of carriers and the metallic Pt content,while the influence of that on the Pt particle dispersion and the enrichment of Pt on surface layer were remarkable.Fluff hydrophobic structure with uniform distribution and serried coverage were more effective to improve the activity of catalyst.Although that structure lead to the decrease of Pt particle dispersion,it could make the Pt particles mostly deposit on the surface layer of the catalysts,which would make more Pt particle participate in the reaction in the same time and the increased catalytic activity could be obtained.