n_x:n_y对PdO/Ce_xZr_yO_2催化剂三效催化性能的影响

Effect of Ce/Zr Atomic Ratio on the TWC Properties of PdO/Ce_xZr_yO_2 Catalysts

采用溶胶-凝胶法制备了一系列CexZryO2(x=0～1,y=1-x)复合氧化物,并以该复合氧化物为载体制备负载贵金属的PdO/CexZryO2催化剂,选择NO-CO反应和CO以及CH4氧化反应为模型反应对催化剂的三效催化性能进行评价,并通过XRD、H2-TPR等手段对载体和催化剂进行初步表征。结果表明:nx:ny对CexZryO2载体及负载PdO催化剂三效催化性能均存在重要影响,不同nx:ny的CexZryO2复合氧化物载体具有不同的晶相结构及还原性能,由其负载的PdO催化剂也各不相同。同时,催化剂的NO还原活性与CO氧化活性与α还原峰存在一定的对应关系。

The CexZryO2(x=0~1, y=1-x) complex oxides was prepared by sol-gel method, and PdO/CexZryO2 catalysts was prepared with it as the carrier. The TWC properties were evaluated using NO-CO reaction and CO-CH4 oxidation reaction as model reaction, and the carrier and catalyst was characterized by XRD and H2-TPR method. Results shown, that the atomic ratio nx:ny had critical impact on the TWC properties of the carrier CexZryO2 and PdO catalyst, and CexZryO2 complex oxides with different nx:ny had different crystalline phase and reduction, and the PdO catalyst carried was different. The PR peak was relating probably to the NO - CO and CO - O2 catalytic activity of PdO/Ce0.8Zr0.2O2 catalysts.