Gold nanoparticles supported on TiO2–Ni as catalysts for hydrogen purification via water–gas shift reaction

Abstract

Gold nanoparticles deposited on TiO₂–Ni prepared by sol–gel process catalyses the CO oxidation to hydrogen purification. Gold-catalysts were characterized by UV-Vis and Raman spectroscopies, X-ray diffraction, H₂-TPR, N₂ physisorption, HRTEM and STEM-HAADF microscopies. These catalysts were applied in the water–gas shift reaction at temperatures from 30 to 300 °C and this reaction was studied by DRIFTS to understand the catalytic surface phenomena. The best CO conversion was showed by doped Au/TiO₂–Ni(1) with regard to Au/TiO₂ sol–gel and Au/TiO₂–P25 catalysts. DRIFTS confirm the strong and favorable effect of doping nickel ions into the reducible TiO₂ framework. Nickel contents from 1 to 10% enhance the WGS reaction in contrast to the undoped catalyst. Ni-doped TiO₂ support was practically inert for WGS reaction. These gold catalysts present significant activity in the water–gas shift reaction that allows purification of hydrogen from industrial sources at low-temperature.