Catalytic decomposition of methanol to carbon monoxide and hydrogen over palladium supported on Ce0.65Zr0.30La0.05O2 and La–Al2O3

In this article, La–Al2O3 and Ce0.65Zr0.30La0.05O2 were used as support to prepare palladium catalyst for methanol decomposition to synthesis gas at low temperature. The catalysts were characterized by nitrogen adsorption, X-ray diffraction (XRD), temperature-programmed reduction (TPR), X-ray photoelectron spectroscopy (XPS) and NH3-temperature-programmed desorption (TPD). XPS results confirm that palladium exists as oxidation state in the two catalysts and has strong interaction with ceria–zirconia solid solution. The result of H2-TPR reveals that the reduction temperature of PdO slightly shifts to high temperature due to the strong interaction between palladium and Ce0.65Zr0.30La0.05O2. For Pd/Ce0.65Zr0.30La0.05O2 catalyst, the higher oxygen storage capacity is beneficial to the Pd species in a more active Pdδ+ state. Furthermore, the results of the methanol decomposition reaction show that the Pd/Ce0.65Zr0.30La0.05O2 catalyst has high catalytic activity. The conversion of methanol achieves 100% at 220 °C over Pd/Ce0.65Zr0.30La0.05O2.

The Pd 3d5/2 binding energy of PCZ catalyst is higher by 0.7 eV than that of PA. The valence of Pd species may be between 0 and +2 in PCZ catalyst, while the cationic species is considered to be highly active in the methanol decomposition.Figure optionsDownload high-quality image (167 K)Download as PowerPoint slideHighlights
► Pd/Ce0.65Zr0.30La0.05O2 has excellent catalytic activity for methanol decomposition to carbon monoxide and hydrogen.
► There is strong interaction between palladium particles and the support in Pd/Ce0.65Zr0.30La0.05O2.
► Palladium in Pd/Ce0.65Zr0.30La0.05O2 catalyst is in cationic state.
► Pd/Ce0.65Zr0.30La0.05O2 catalyst has large OSC and is well dispersed.
► Pd/Ce0.65Zr0.30La0.05O2 catalyst has great potential for practical application.