Cu_xCo_(1-x)/Al_2O_3/FeCrAl整体式催化剂上甲苯催化燃烧(英文)

以FeCrAl合金薄片为基底,Al2O3浆料为过渡胶体,不同摩尔比的Cu、Co为催化活性组分,制备了一系列CuxCo1-x/Al2O3/FeCrAl(x=0-1)新型整体式催化剂.采用X射线粉末衍射(XRD),扫描电子显微镜(SEM),X光电子能谱(XPS)和程序升温还原(TPR)等手段对催化剂的结构进行了表征.在微型固定床反应器上评价了催化剂的催化甲苯燃烧性能.研究结果表明:在所制备的整体式催化剂上,当Cu含量比较低时,形成了Cu-Co-O固溶体;当Cu含量比较高时,可以测得CuO的衍射峰.催化剂表面颗粒大小和形貌与Cu、Co摩尔比密切相关.在催化剂表面,Co以Co2+和Co3+价态存在,而Cu主要以Cu2+价态存在.催化剂中的Cu可以改善Co的氧化还原性,从而有利于催化剂活性的提高.在所制备的催化剂中,Cu0.5Co0.5/Al2O3/FeCrAl催化剂具有最好的活性,甲苯在374oC可以完全催化燃烧消除.

Catalytic Combustion of Toluene over CuxCo1-x/Al2O3/FeCrAl Monolithic Catalysts

A series of Cu_xCo_1-x/Al₂O₃/FeCrAl (x=0-1) catalysts were prepared using an FeCrAl alloy as support, a boehmite primer sol as the first washcoat layer and copper as well as cobalt oxides as the active washcoat layer. The structure of the catalysts was characterized using X-ray powder diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and temperatureprogrammed reduction (TPR). Toluene was chosen as the model compound to evaluate the catalytic activity in a conventional fixed-bed quartz reactor. Results indicate that a Cu-Co-O solid solution phase was present when the content of Cu in the catalysts was low and a CuO phase was present when the content of Cu was high. Both Co²⁺ and Co³⁺ were present on the surface of the obtained monolithic catalysts while Cu²⁺ was the main Cu species. The addition of a proper amount of copper oxide improved the reducibility of the cobalt oxide, which enhanced the catalytic activity of the catalysts. All the obtained catalysts showed good activity for the catalytic combustion of toluene. The Cu_0.5Co_0.5/Al₂O₃/FeCrAl catalyst had the best catalytic activity, and toluene was totally oxidized at 374 °C over it.