Investigation on gold dispersion of Au/ZrO2 catalysts and activity in the low-temperature WGS reaction

Gold over zirconia and sulfated zirconia catalysts were tested in the water–gas shift (WGS) reaction at temperatures between 423 and 453 K. Samples were characterized by N2 adsorption analysis, XRD, TPO, TG-DTA and pulse-flow CO chemisorption. A very good linear relationship between catalytic activity and dispersion determinated by chemisorption has been evidenced. Sulfated catalysts showed higher activities than samples over plain zirconia. SO4= do not behave as promoters of the gold active phase, but they yield a larger specific surface area of the zirconia, thus favouring a better dispersion of gold nanoparticles on the support. CO amount at the reactor outlet has been checked and will be discussed.