Au@ Al2O3 3DOM复合材料的可控制备及催化性能研究

Controllable Preparation of Au@3DOM Composite Structure and its Catalytic Performance

摘要:

采用胶体晶体模板方法,通过调控聚苯乙烯(PS)微球粒径和前驱体浓度制备了孔径由0.48 μm至1.65 μm连续可调的Au@Al₂O₃ 三维有序大孔(3DOM)复合材料。利用扫描电子显微镜(SEM)、X射线衍射(XRD)和紫外－可见分光光度计(UV-Vis)等手段考察了样品的表面形貌和催化特性。发现Au@Al₂O₃3DOM复合材料具有优异的催化性能。随着孔径增大,其催化性能表现出先上升后下降的变化规律,且在孔径为1.27 μm时达到最高。结合理论分析表明,Au@Al₂O₃3DOM 复合材料的微观结构变化,导致了其有效活性面积和孔道传输效率随之改变,二者的共同作用是Au@Al₂O₃3DOM复合材料催化性能变化规律的物理本质。

Abstract:

Highly ordered Au@Al₂O₃3DOM composites with different pore diameters, including0.48, 0.96, 1.27, 1.49 and 1.65μm, were prepared via infilling Al₂O₃ into the gaps of PS colloidal crystal templates with colloidal crystal template techniquce. The morphology characters and catalytic activity of Au@Al₂O₃ 3DOM composites were characterized by SEM, XRD and UV-Vis spectrometer, respectively. It was found that Au@Al₂O₃3DOM composites had excellent catalytic performance. As the pore diameters increased, the catalytic performance increasedSrapidly and then decreased gradually. The catalytic activity was highest, when the pore size of the composite material reached1.27 μm. The results of theoretical analysis indicated that effective active area and channel transmission efficiency varied with the change of the microstructure, and the competition between the effective active area and the channel transmission efficiency resulted in the chang of the catalytic performance.