One dimensional Pt/CeO2-NR catalysts for hydrogen production by steam reforming of methanol: Effect of Pt precursor

Abstract

Abstract Pt nanocatalysts supported on CeO2-NR (CeO2-nanorods) were synthesized and evaluated in the steam reforming of methanol reaction (SRM) for hydrogen production. The effect of Pt precursor was investigated using tetraaminplatinum nitrate (Pt(NH3)4(NO3)2), platinum acetylacetonate (CH3-COCHCO-CH3)2Pt and hexachloroplatinic acid (H2PtCl6*6H2O). The catalysts were characterized by N2 Adsorption-Desorption (BET), MEB, DRX, TPR, HAADF-STEM, Mass Spectroscopy (MS) and DRIFT. All samples showed typical diffraction peaks of the fluorite CeO2 phase cubic structure. TPR profiles of Pt/CeO2-NR(Nit) and Pt/CeO2-NR(Acac) catalysts, showed reduction peaks at temperatures lower compared with those of Pt/CeO2-NR(Cl) catalysts. STEM-HAADF characterization revealed the presence of small Pt nanoparticles on Pt/CeO2-NR(Nit) but not for Pt/CeO2-NR(Acac); this finding was associated with the catalysts synthesis solvent used. Pt/CeO2-NR(Nit) sample showed the best performance on methanol conversion than other catalysts, this result was associated with a larger number Pt nanoparticles distributed along the CeO2-NR. Low catalytic activity observed on the Pt/CeO2-NR(Cl) sample, was associated with formation of oxychlorinated PtxOyClz species. Although MS technique showed stable methanol conversion during the reaction, no further changes in the outlet signals on the real-time monitoring analysis by MS was observed, this indicates that the catalyst was very stable during the reaction.