热处理对负载Pd-Pt双金属及其单金属催化剂的还原性能的影响

Effect of Thermal Treatment on Reducibility of Pd,Pt,and Pd-Pt Supported on Al_2O_3

采用程序升温还原(TPR)技术研究了热处理对负载于 Al_2O_3上的 Pd-Pt 双金属及其单金属催化剂的还原性能的影响。发现热处理温度和气氛的变化对 Pd/Al_2O_3和 Pt/Al_2O_3单金属催化剂以及 Pd-Pt/Al_2O_3双金属催化剂的 TPR 曲线有着明显的影响。Pd-Pt/Al_2O_3及其单金属催化剂的TPR 曲线亦有着明显的差异,其还原峰位发生明显的位移。讨论了负载于 Al_2O_3上的 Pd-Pt 双金属及其单金属催化剂在还原过程中金属与金属、金属与载体之间的相互作用以及热处理条件对其催化剂的还原性能的影响。

The effect of thermal treatment on the reducibility of the Al_2O_3-supported Pd-Pt bimetallic and its mono-metal catalysts has been investigated with tem- perature-programmed reduction(TPR)technique.It is found that when these catalysts are treated at different temperatures,different TPR profiles are produced.And there is obvious difference between the TPR profiles of the Al_2O_3-supported Pd- Pt bimetallic and its mono-metal catalysts.Displacement in reduction peaks are also observed.There is indication that interactions occur between Pd and Pt,Pd and Al_2O_3,and Pt and Al_2O_3 in the catalysts during reduction process.The results showed that the reducibility of these catalysts is affected by variations in the thermal treatment conditions.