铜基廉价催化剂的火焰合成及甲烷催化特性研究

Studies on Flame-synthesized Low-cost Cu-based Catalysts and the Catalytic Properties

本文基于预混滞止弱旋火焰系统,以溶于水或乙醇的廉价硝酸盐为前驱物,采用"一步"的雾化火焰方法来合成铜基催化剂纳米颗粒。采用TEM、XRD等分析了合成颗粒的形貌及物相态,进而考察了该催化剂在甲烷催化氧化反应中的催化活性。根据TEM结果,发现乙醇做溶剂时所合成的氧化铜颗粒具有颗粒直径小且结晶度较好的特点。实验结果表明,10 nm氧化铜颗粒体现出良好的甲烷催化性能,但掺杂氧化铝后,铜基催化剂对甲烷的催化性能有所下降,其原因可归结为氧化铝对氧化铜的覆盖作用导致其有效比表面积降低。

One-step spray flame synthesis,on the basis stagnation swirl burner,is developed to synthesize low-cost Cu-based catalysts.When preparing the solution,copper nitrate trihydrate and ethyl alcohol are used as precursor and solvent,respectively.BET and XRD analyses are adopted to characterize the catalysts,and then the catalytic activity of methane oxidation is determined by a lab-scale fixed-bed micro-reactor.The TEM results indicate that the copper oxide nanoparticles prepared with the ethyl alcohol solvent exhibit ultrafine diameter and good crystallinity,which are more suitable for the catalytic oxidation.Finally,10 nm CuO particles show good catalytic performance for methane,however the catalytic performance decreases after doping with alumina.It can be explained that the effective ratio of copper oxide declines because of the shingling effects caused by alumina.