Catalytic performance of bimetallic Ni-Pt nanoparticles supported on activated carbon, gamma-alumina, zirconia, and ceria for hydrogen production in sulfur-iodine thermochemical cycle

摘要

Bimetallic Ni-Pt nanoparticles supported on four different supports (activated carbon (AC)), gamma-alumina, zirconia, and ceria) were prepared by modified impregnation-reduction technique for decomposition of hydrogen iodide to hydrogen and iodine, in the thermochemical water-splitting sulfur-iodine (SI) cycle. The catalysts were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) method to find their structure, morphology, and surface area, respectively. High metal dispersions (Ni-Pt) were obtained with particle sizes of the order of 10 nm or lesser, in the high-surface-area supports. The hydrogen iodide-decomposition results showed catalytic activity of Ni-Pt nanoparticles in the following order on different supports: Ni(2.5%)-Pt(2.5%)/AC > Ni(2.5%)-Pt(2.5%)/gamma-alumina > Ni(2.5%)-Pt(2.5%)/Zirconia > Ni(2.5%)-Pt(2.5%)/Ceria. Bimetallic Ni(2.5%)-Pt(2.5%)/AC also showed excellent stability for 100 h in the hydrogen iodide-decomposition reaction, and with a higher performance relative to the corresponding Pt supported catalyst under the same operating conditions. (C) 2016 Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC.