球磨法制备的Cu基催化剂应用于乙酸乙酯催化燃烧反应的研究

The study of Cu-based catalysts by ball-milling for ethyl acetate catalytic combustion

挥发性有机废气(volatile organic compounds,VOCs)的大量排放对环境造成了严重危害,催化燃烧是去除VOCs的有效方法之一。使用简单且环保的催化剂制备方法一直是催化燃烧中催化剂研究的重点与难点之一。以CeO_(2),Al_(2)O_(3),La_(2)O_(3)和ZrO_(2)等氧化物以及相应的氢氧化物为载体前驱体,采用球磨法制备了一系列负载型Cu基催化剂,比较了不同氧化物和相应氢氧化物载体前驱体对乙酸乙酯(ethyl acetate,EA)催化燃烧性能的影响,并用XRD、TEM、XPS和H_(2)-TPR等对催化剂进行了表征。结果表明,除Al(OH)_(3)外,以氢氧化物为载体前驱体的催化剂还原性能更好、表面高分散CuO相对质量分数更高、EA催化燃烧的性能更优。除10%-Cu-Al(AlH)催化剂外,10%-Cu-YH比10%-Cu-Y具有更高催化活性的原因之一是前者形成了更小尺寸的纳米复合物。此外,催化剂的活性与催化剂表面的氧物种比例(O_(ads)/O_(latt))呈正相关。在所制备的Cu基催化剂中,以Ce(OH)_(4)和Zr(OH)_(4)为载体前驱体制备的10%-Cu-CeH(T_(50)=214℃,T_(95)=238℃)和10%-Cu-ZrH(T_(50)=217℃,T_(95)=239℃)催化剂在EA催化燃烧中的性能更好,具有潜在的工业应用价值。研究结果可为VOCs催化燃烧的负载型非贵金属催化剂设计和制备提供参考。

The massive emission of VOCs has caused serious harm to the environment.Catalytic combustion is an efficient way of eliminating VOCs.However,how to prepare catalysts for VOCs elimination with simple and ecofriendly methods is still a big challenge.In our study,supported Cu-based catalysts for catalytic combustion of ethyl acetate(EA)were prepared using the ball-milling method with CeO_(2),Al_(2)O_(3),La_(2)O_(3) and ZrO_(2) and their corresponding hydroxides as support precursors.The prepared catalysts were characterized by XRD,TEM,XPS and H_(2)-TPR.The results show that the catalysts with hydroxides as support precursors have better reduction performance,higher content of highly dispersed CuO on the surface,and better catalytic combustion performance of ethyl acetate,except for the catalyst prepared with aluminum hydroxide precursor catalyst.Except for the 10%-Cu-Al(AlH),one of the main reasons that the catalytic activities of the 10%-Cu-YH is that the former forms smaller nanocomposites.In addition,higher ratio of Oads/Olatt is also ascribed to higher catalytic performance of 10%-Cu-CeH than the 10%-Cu-Ce.Among them,10%-Cu-CeH(T50=214℃,T95=238℃)and 10%-Cu-ZrH(T50=217℃,T95=239℃)prepared with Ce(OH)_(4) and Zr(OH)_(4) as support precursors catalyst has the best performance in the catalytic combustion of EA.The above results provide a new idea for the design and preparation of supported non-precious metal catalysts for the catalytic combustion of VOCs.