焙烧气氛对Pt/Al2O3 催化氧化CO和C3H6 性能的影响

Effect of Calcination Atmospheres on Catalytic Perfor-mance of Pt/Al2O3 for Oxidation of CO and C3H6

摘要:

使用Pt(NH₃)₂(NO₂)₂作为前驱体，通过过量浸渍法制备Pt/Al₂O₃催化剂，并将其在4种不同的气氛（H₂、O₂、NO或NH₃）中进行焙烧。利用N₂吸脱附、X射线衍射、程序升温还原（H₂-TPR）、CO脉冲吸附、CO原位漫反射傅里叶变换红外光谱（CO in situ DRIFTS）等手段对催化剂的物化性质进行了表征。结果表明：由于还原性焙烧气氛导致了众多小尺寸和高分散的Pt纳米颗粒的生成，经1%（体积分数）H₂/N₂焙烧的Pt/Al₂O₃表现出最佳的CO和C₃H₆催化氧化性能。

Abstract:

Pt/Al₂O₃ catalysts were prepared by an excess impregnation method with Pt(NH₃)₂(NO₂)₂ as the precursor. Then they were calcined in four different atmospheres (H₂, O₂, NO, NH₃), and characterized by N₂ adsorption and desorption test, X-ray diffraction, H₂-temperature programmed reduction (TPR) test, CO pulse adsorption test, and CO in-situ diffuse reflectance infrared Fourier transform spectroscopy (CO in situ DRIFTS). Results show that Pt/Al₂O₃ catalyst calcined in 1vol% H₂/N₂ atmosphere exhibits the best catalytic oxidation performance for CO and C₃H₆, because of the generation of numerous small-sized and highly dispersed Pt nanoparticles caused by the reducing calcination atmosphere.