摘要
Gold nanoparticles supported on iron oxides are highly active catalysts for the oxidation of CO even at low temperature [1,2]. In the present work, a series of Au@Fe_2O_3-hollow catalysts with different hollow sizes(10-25 nm) were obtained via a novel synthetic strategy. Au/β-FeOOH-rods and Au/β-FeOOH-cubes prepared by hydrothermal processes were used as precursors, and the different hollow structural features of Au@Fe_2O_3 catalysts were synthesized by controlling the sizes of the FeOOH rods or cube and the calcination conditions. Characterization techniques, such as X-ray diffraction(XRD), transmission electron microscopic(TEM), thermogravimetry differential scanning calorimeter(TG–DSC), X-ray photoelectron spectroscopy(XPS), H_2 or CO temperature programmed reduction(H_2/CO-TPR), CO_2 temperature programmed desorption(CO_2-TPD) and In-situ Fourier transformed infrared(FTIR) spectroscopy were employed to investigate the structure, surface morphology and physical-chemical properties of the catalysts. The structural susceptibility of Au@Fe_2O_3 catalysts for CO oxidation was investigated in detail. The sample with a metal loading of 1 wt % shows good activity, which is much better than the Au/Fe_2O_3-bulk prepared by colloidal deposition with more gold loadings(e.g., 3%). This should be attributed to abundant interface between the Au particles and Fe_2O_3 in the hollow structure. The catalytic activity of the Au@Fe_2O_3 was also affected by the hollow size.
Gold nanoparticles supported on iron oxides are highly active catalysts for the oxidation of CO even at low temperature [1,2]. In the present work, a series of Au@Fe_2O_3-hollow catalysts with different hollow sizes(10-25 nm) were obtained via a novel synthetic strategy. Au/β-FeOOH-rods and Au/β-FeOOH-cubes prepared by hydrothermal processes were used as precursors, and the different hollow structural features of Au@Fe_2O_3 catalysts were synthesized by controlling the sizes of the FeOOH rods or cube and the calcination conditions. Characterization techniques, such as X-ray diffraction(XRD), transmission electron microscopic(TEM), thermogravimetry differential scanning calorimeter(TG–DSC), X-ray photoelectron spectroscopy(XPS), H_2 or CO temperature programmed reduction(H_2/CO-TPR), CO_2 temperature programmed desorption(CO_2-TPD) and In-situ Fourier transformed infrared(FTIR) spectroscopy were employed to investigate the structure, surface morphology and physical-chemical properties of the catalysts. The structural susceptibility of Au@Fe_2O_3 catalysts for CO oxidation was investigated in detail. The sample with a metal loading of 1 wt % shows good activity, which is much better than the Au/Fe_2O_3-bulk prepared by colloidal deposition with more gold loadings(e.g., 3%). This should be attributed to abundant interface between the Au particles and Fe_2O_3 in the hollow structure. The catalytic activity of the Au@Fe_2O_3 was also affected by the hollow size.
引文
[1]T.Yan,D.W.Redman,W.Y.Yu,D.W.Flaherty,J.A.Rodriguez,C.B.Mullins,J.Catal.,294(2012).216.
[2]H.F.Yin,Z.Ma,M.F.Chi,S.Dai,Catal.Today,160(2011).87.