Fully Reversible Metal Deactivation Effects in Gold/Ceria–Zirconia Catalysts: Role of the Redox State of the Support

Abstract

Strong and reversible modification of the chemical properties of supported Au nanoparticles caused by alternating oxidizing (a and c) and reducing (b) pretreatment of Au/CeO2–ZrO2 catalysts were revealed by a methodology that combines FTIR spectroscopy (see picture), studies on the volumetric adsorption of CO and ultimate oxygen storage capacity, determination of metal dispersion by electron microscopy, and X‐ray photoelectron spectroscopy.

Improving the Redox Response Stability of Ceria-Zirconia Nanocatalysts under Harsh Temperature Conditions

“…The Kratos coaxial charge neutralization system was used to compensate charging effects, and the binding energy scale was calibrated with respect to Zr 3d5/2 component at 182.64 eV. 31 The spectrometer was connected to a catalytic cell which allowed the reduction of samples and their anaerobic transfer to the analysis chamber.…”

Designed synthesis and formation mechanism of CeO2hollow nanospheres and their facile functionalization with Au nanoparticles

“…52,53 It also demonstrated by a strong metal-support interaction at the interfaces, which improves the reducibility of the surface oxygen on the CeO 2 support. 54,55 Notably, the reduction signal appearing below 200 °C is broaden and asymmetric, resulting from the reduction of several forms of oxygen species on the surface of ceria. 56,57 It might be associated with a partial reduction of surface oxygen attached to a surface Ce 4+ ion and the rest due to the reduction of cationic Au species.…”

Classical strong metal–support interactions between gold nanoparticles and titanium dioxide

“…Progress on practical catalyst systems has uncovered an O 2 -induced SMSI for gold supported on ZnO nanorods ( 40 ) and hydroxyapatite ( 18 , 19 ), the reverse of conditions required for classical SMSI. However, decreased CO adsorption was reported following the reduction of Au/CeO 2 ( 41 ), hinting at the existence of classical SMSI effects in gold catalysis. Here, we report the unequivocal discovery of a classical SMSI in Au/TiO 2 , evidenced by encapsulation of gold particles by partially reduced titania and accompanied by suppressed CO adsorption and enhanced catalytic stability for CO oxidation.…”