A Novel Process for Preparation of Unsupported Mesoporous Intermetallic NiZn and PdZn Catalysts

Abstract

Unsupported mesoporous intermetallic (usmpIM) NiZn and PdZn catalysts are successfully prepared by means of a two-step procedure: (1) leaching of Al-based intermetallic compounds (Al3Ni, Al21Pd8) with 20 wt% NaOH aqueous solution and (2) immersion of ZnCl2 aqueous solution into unsupported porous Ni or Pd followed by alloying treatment under H2 flow at 500 °C, i.e., immersion alloying process. Thermal stability of the mesoporous structures is found to be improved by alloying with Zn. The catalytic properties for steam reforming of methanol (SRM) were completely different from the original unsupported porous Ni and Pd, where the decomposition of methanol and the SRM occurred preferentially on usmpIM NiZn and usmpIM PdZn, respectively.