机构地区: 华南理工大学化学与化工学院传热强化与过程节能教育部重点实验室
出 处: 《高校化学工程学报》 2006年第3期368-373,共6页
摘 要: 对在超声场下制备得到的CuO/γ-Al2O3催化剂与常规的浸渍法制备的CuO/γ-Al2O3催化剂进行了对比研究,分别进行催化氧化(燃烧)销毁甲苯和苯的实验,并用SEM,XRD,TPR和XPS对所制备的催化剂进行表征。研究结果表明:使用超声场下制备得到的CuO/γ-Al2O3作为催化剂的活性明显高于普通浸渍法制备得到的CuO/γ-Al2O3催化剂的活性。SEM分析表明,在超声场下制备的CuO/γ-Al2O3催化剂表面上的CuO晶体颗粒较小,且分布均匀;XRD分析表明超声促进了活性组分铜在表面的分散,CuO在催化剂表面由晶体向高分散的非晶相型转变。TPR分析表明在超声场下制备的CuO/γ-Al2O3催化剂中活性组分铜还原的途径从Cu(Ⅱ)还原到Cu(Ⅰ),再从Cu(Ⅰ)还原到金属铜,这有助于增强催化剂中Cu的还原性;XPS表征分析显示,在超声场下制备的CuO/γ-Al2O3催化剂与用普通浸渍法制得的CuO/γ-Al2O3相比,Cu2p3/2的结合能由934.2eV变到933.1eV,在催化剂表面呈现出Cu2+和Cu+的混合形式。 Besides using the conventional impregnation method, the CuOγ -Al2O3 catalysts, which are used for catalytic combustion of volatile organic compounds (VOCs), were also prepared separately by the impregnation method assisted with ultrasonic treatment. Using these catalysts prepared , the catalytic combustions of two kinds of VOCs, toluene and benzene, were carried out experimentally. The surface properties of these catalysts were characterized by scanning electron micrograph (SEM), X-ray diffraction (XRD), temperature-programmed reduction with H2 (H2-TPR) and X-ray photoelectron spectroscopy (XPS). The experimental results show that during catalytic combustion of VOCs, the activity of the CuO/γ -Al2O3 catalysts prepared with using ultrasonic treatment is much higher than that of prepared by conventional impregnation method. SEM shows that the use of ultrasound makes the CuO particle size of CuO/γ -Al2O3 catalyst prepared with using ultrasound much smaller than that of prepared by conventional impregnation method. XRD results show that the use of ultrasound causes the Cu ions highly disperse on the CuO/γ -Al2O3 catalysts. TPR shows that ultrasound makes the CuO reduction occurs in two steps, that is from Cu(Ⅱ ) to Cu(Ⅰ) and then from Cu(Ⅰ) to metallic copper. XPS analysis indicates that comparing with the CuO/γ -Al2O3 catalysts prepared by conventional impregnation method, the binding energy level of the catalysts prepared with using ultrasound decrease from 934.2 eV to 933.1 eV, which indicates that the Cu existing on the catalyst surface is in the form of Cu^2+ and Cu^+.