Catalytic decomposition of N2O over Rh/Zn-Al2O3 catalysts
Catalytic decomposition of N2O over Rh/Zn-Al2O3 catalysts
复制标题
Rh/Zn-Al2O3 催化剂催化分解 N2O
作者：
Huang C.Y.;Ma Z.;Miao C.X.;Yue Y.H.;Hua W.M.;Gao Z.
将工业γ-Al_2O_3粉末浸渍不同量的Zn(NO_3)_2，然后在500℃或800℃的空气中焙烧制备了Rh/Zn-Al_2O_3催化剂，然后用Rh(NO_3)_3浸渍法制备了Rh/Zn-Al_2O_3催化剂。结果表明，当焙烧温度为500℃时，载体为ZnO/Al_2O_3(负载在Al_2O_3上)，而在800℃焙烧时，在Al_2O_3表面形成了尖晶石结构的锌铝尖晶石，Rh/Zn-Al_2O_3催化剂的活性远高于Rh/Al_2O_3和Rh/ZnO。与其他催化剂相比，Rh/Zn-Al_2O_3-800催化剂(Rh/Zn-Al_2O_3-800)具有最小的Rh2O_3颗粒尺寸和较低的脱附温度。这两个因素都可能是实现高活性N2O分解的重要因素。
Zn–Al2O3 supports were prepared by impregnating commercial γ-Al2O3 powders with different amounts of Zn(NO3)2, followed by calcination in air at 500 or 800 °C. Rh/Zn–Al2O3 catalysts were then prepared by impregnating Zn–Al2O3 supports with Rh(NO3)3 followed by calcination in air at 500 °C. The catalysts and/or supports were characterized by ICP-OES, XRD, N2 adsorption, Raman spectroscopy, TEM-EDX, XPS, CO2-TPD, H2-TPR, and O2-TPD, and the catalytic performance of supported Rh catalysts in N2O decomposition was tested. It is concluded that the support can be described as ZnO/Al2O3 (ZnO supported on Al2O3) when calcining Zn(NO3)2/Al2O3 at 500 °C, whereas ZnAl2O4 spinel forms on the Al2O3 surface at 800 °C. Rh/Zn–Al2O3 catalysts are much more active than Rh/Al2O3 and Rh/ZnO. The best catalyst (Rh/Zn–Al2O3-800 with 1 wt% Rh and 1 wt% Zn) has the smallest Rh2O3 particle size and can desorb O2 at lower temperature than other catalysts. Both factors may be important for achieving high activity in N2O decomposition.