Effect of Different Supports on Performance of Palladium Methanol Decomposition Catalyst

Abstract:

Two kinds of palladium methanol decomposition catalysts were prepared by immersion method with γ-Al2O3 and Ce0.65Zr0.35O2 as supports, respectively. XRD, XPS, H2-TPR (H2-Temperature-Programmed-Redution) and NH3-TPD (NH3-Temperature- Programmed Desorption) techniques were used to study the microstructure and performance of catalyst samples and the activity of methanol low-temperature decomposition for the catalysts was also investigated. Testing results show that the Pd/Ce0.65Zr0.35O2 catalyst possesses weak surface acidity and good low-temperature reducibility. XPS results confirm that palladium of the two catalysts exist as oxidation state. Combining with catalytic activity, it can be known that Pd+ is advantageous in the methanol decomposition. High dispersion of palladium in ceria-zirconia solid solution and strong interaction between Pd and supports can decrease activation energy which results in high catalytic activity for methanol decomposition. The conversion of methanol nearly achieved 100% at 220 ℃ for Pd/Ce0.65Zr0.35O2.

Key words:γ-Al2O3; Ce0.65Zr0. 35O2; palladium based catalyst; methanol decomposition