Study of the oxidation by water of Au/CeGaOx catalysts active in the WGS reaction

J. VECCHIETTI; S. E. COLLINS; L. BARRIOS; D. STACCHIOLA; S. BERNAL; A. BONIVARDI

Upton

Congreso; 4th International Congress on Operando Spectroscopies; 2012

We have investigated the synthesis and catalytic activity of catalysts supported on CeGaOx mixed oxides, which show an improved reducibility as compared with pure ce-ria. Gold supported catalysts on both CeO2 and CeGaOx show activity towards the wa-ter gas shift (WGS) reaction [1,2]. It has been suggested in the literature that the WGS reaction on gold based catalysts proceeds via a redox mechanism. CO initially adsorbs on the metal sites and from there reduces the oxide support. The support is then re-oxidized by water [3], being this the rate limiting step. Thus, we studied the reoxidation by water of the Au/CeO2 and Au/CeGaOx catalysts (Ce/Ga = 75/25, 80/20, and 95/5 mol/mol, coded Ce75Ga25, Ce80Ga20 and Ce95Ga05, respectively) by time-resolved X-ray diffraction (XRD) and infrared spectroscopy (DRIFT) coupled with Mass Spectrometry (MS). Preliminary results for the WGS reaction on these catalysts during operando conditions obtained by DRIFTS, XRD and XAS will be presented.