Effect of yttrium addition on water-gas shift reaction over CuO/CeO2 catalysts

This paper presented a study on the role of yttrium addition to CuO/CeO2 catalyst for water-gas shift reaction. A single-step co-precipitation method was used for preparation of a series of yttrium doped CuO/CeO2 catalysts with yttrium content in the range of 0–5wt.%. Properties of the obtained samples were characterized and analyzed by X-ray diffraction (XRD), Raman spectroscopy, H2-TPR, cyclic voltammetry (CV) and the BET method. The results revealed that catalytic activity was increased with the yttrium content at first, but then decreased with the further increase of yttrium content. Herein, CuO/CeO2 catalyst doped with 2wt.% of yttrium showed the highest catalytic activity (CO conversion reaches 93.4% at 250 °C) and thermal stability for WGS reaction. The catalytic activity was correlated with the surface area, the area of peak γ of H2-TPR profile (i.e., the reduction of surface copper oxide (crystalline forms) interacted with surface oxygen vacancies on ceria), and the area of peak C2 and A1 (Cu0↔Cu2+ in cyclic voltammetry process), respectively. Besides, Raman spectra provided evidences for a synergistic Cu-Ovacancy interaction, and it was indicated that doping yttrium may facilitate the formation of oxygen vacancies on ceria.

[1]  M. Flytzani-Stephanopoulos,et al.  Nanostructured Au–CeO2 Catalysts for Low-Temperature Water–Gas Shift , 2001 .

[2]  W. Weber,et al.  Raman and x‐ray studies of Ce1−xRExO2−y, where RE=La, Pr, Nd, Eu, Gd, and Tb , 1994 .

[3]  G. Avgouropoulos,et al.  Selective CO oxidation over CuO-CeO2 catalysts prepared via the urea-nitrate combustion method , 2003 .

[4]  Shurong Wang,et al.  Preparation and characterization of CuO/CeO2 catalysts and their applications in low-temperature CO oxidation , 2005 .

[5]  M. S. Hegde,et al.  Promoting effect of CeO2 in a Cu/CeO2 catalyst: lowering of redox potentials of Cu species in the CeO2 matrix , 2001 .

[6]  J. Papavasiliou,et al.  Effect of additives on the WGS activity of combustion synthesized CuO/CeO2 catalysts , 2007 .

[7]  A. Basińska,et al.  The influence of alkali metals on the activity of supported ruthenium catalysts for the water-gas shift reaction , 1997 .

[8]  D. Chadwick,et al.  Reactivity of ceria, Gd- and Nb-doped ceria to methane , 2002 .

[9]  X. Yian,et al.  Spontaneous Monolayer Dispersion of Oxides and Salts onto Surfaces of Supports: Applications to Heterogeneous Catalysis , 1990 .

[10]  F. Zhang,et al.  Improved Performance of Au/Fe2O3 Catalysts Promoted with ZrO2 and Nb2O5 in the WGS Reaction under Hydrogen-rich Conditions , 2006 .

[11]  Maria Flytzani-Stephanopoulos,et al.  Low-temperature water-gas shift reaction over Cu- and Ni-loaded cerium oxide catalysts , 2000 .

[12]  G. Petot-ervas,et al.  Microstructure and transport properties of Y-doped zirconia and Gd-doped ceria , 2003 .

[13]  Kangnian Fan,et al.  Effect of preparation method on the hydrogen production from methanol steam reforming over binary Cu/ZrO2 catalysts , 2006 .

[14]  Yi Chen,et al.  Surface interaction model ofγ-alumina-supported metal oxides , 1992 .

[15]  M. Flytzani-Stephanopoulos,et al.  Activity and Stability of Cu−CeO2 Catalysts in High-Temperature Water−Gas Shift for Fuel-Cell Applications , 2004 .

[16]  Zhong‐Yong Yuan,et al.  Titanium oxide nanotubes as supports of nano-sized gold catalysts for low temperature water-gas shift reaction , 2005 .

[17]  Xiaolan Song,et al.  Synthesis and Characterization of Y-Doped Mesoporous CeO2 Using A Chemical Precipitation Method , 2007 .

[18]  William J. Dawson,et al.  Fuel processing catalysts based on nanoscale ceria , 2001 .

[19]  L. Gauckler,et al.  Engineering of Solid Oxide Fuel Cells with Ceria‐Based Electrolytes , 1998 .

[20]  T. Nakagawa,et al.  XAFS and XRD study of ceria doped with Pr, Nd or Sm , 2004 .

[21]  Junjiang Zhu,et al.  Application of cyclic voltammetry in heterogeneous catalysis: NO decomposition and reduction , 2005 .

[22]  In situ ATR-IR spectroscopic and reaction kinetics studies of water-gas shift and methanol reforming on Pt/Al2O3 catalysts in vapor and liquid phases. , 2005, The journal of physical chemistry. B.

[23]  Raymond J. Gorte,et al.  Deactivation Mechanisms for Pd/Ceria During the Water-Gas Shift Reaction , 2002 .

[24]  Q. Xin,et al.  Carbon monoxide oxidation over CuO/CeO2 catalysts , 2004 .

[25]  U. Graham,et al.  Low-Temperature Water-Gas Shift: In-Situ DRIFTS−Reaction Study of a Pt/CeO2 Catalyst for Fuel Cell Reformer Applications , 2003 .

[26]  Junjiang Zhu,et al.  Study of La2−xSrxCuO4 (x = 0.0, 0.5, 1.0) catalysts for NO + CO reaction from the measurements of O2-TPD, H2-TPR and cyclic voltammetry , 2005 .

[27]  Wenjie Shen,et al.  Oxidative steam reforming of methanol on Ce0.9Cu0.1OY catalysts prepared by deposition–precipitation, coprecipitation, and complexation–combustion methods , 2004 .

[28]  David L. Trimm,et al.  Minimisation of carbon monoxide in a hydrogen stream for fuel cell application , 2005 .