2 - Highly active and reusable nanocomposites for hydrogen generation

Abstract

In this study, a simple and reproducible production method at room temperature of the monodispersed Pd-Ni nanoparticles supported on activated carbon (AC) was explained. To produce these nanoparticles, a sodium hydroxide-assisted reduction method combined with simultaneous reduction was used that employed no stabilizer. The nanoparticles were characterized by an ultraviolet-visible spectrophotometer, X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The results showed that Pd-Ni nanoparticles were highly monodispersed on their supporting material (AC), and had an approximate size of 3.55±0.42nm. For the aim of catalytic decomposition of dimethyl ammonia borane (DMAB) as a safe and convenient hydrogen carrier for fuel cells under mild conditions, the produced activated carbon-supported Pd-Ni nanoparticles were utilized. As a result, the produced NPs catalyzed the DMAB dehydrogenation with high catalytic activity (TOF=316.41) at room temperature. In addition, Pd-Ni @AC NPs had good stability and no agglomeration; leaching and CO poisoning were observed. The Pd-Ni catalyst carried most (~81%) of its own activity after six reuses in the DMAB dehydrogenation at complete conversion. Moreover, the present study shows the kinetic data compilation for the Pd-Ni NPs catalyzed DMAB dehydrogenation and determines the catalytic reaction parameters (Ea, ΔH#, and ΔS#).