Gold catalysts supported on ceria-modified mesoporous zirconia for low-temperature water–gas shift reaction

Abstract

New gold catalytic system prepared on ceria-modified mesoporous zirconia used as water–gas shift (WGS) catalyst is reported. Mesoporous zirconia was synthesized using surfactant templating method through a neutral [C13(EO)6-Zr(OC3H7)4] assembly pathway. Ceria modifying additive was deposited on mesoporous zirconia by deposition–precipitation method. Gold-based catalysts with different gold content (1–3 wt. %) were synthesized by deposition–precipitation of gold hydroxide on mixed metal oxide support. The supports and the catalysts were characterized by powder X-ray diffraction, high-resolution transmission electron microscopy, N2 adsorption analysis and temperature programmed reduction. The catalytic behavior of the gold-based catalysts was evaluated in WGS reaction in a wide temperature range (140–300 °C) and at different space velocities and H2O/CO ratios. The influence of gold content and particle size on the catalytic performance was investigated. The WGS activity of the new Au/ceria-modified mesoporous zirconia catalysts was compared with that of gold catalysts supported on simple oxides CeO2 and mesoporous ZrO2, revealing significantly higher catalytic activity of Au/ceria-modified mesoporous zirconia. A high degree of synergistic interaction between ceria and mesoporous zirconia and a positive modification of structural and catalytic properties by ceria have been achieved. It is clearly revealed that the ceria-modified mesoporous zirconia is of much interest as potential support for gold-based catalyst. The Au/ceria-modified mesoporous zirconia catalytic system is found to be effective catalyst for WGS reaction.