Ceria and Gold/Ceria Catalysts for the Abatement of Polycyclic Aromatic Hydrocarbons: An In Situ DRIFTS Study

Abstract

Gold catalysts supported on nano-crystalline ceria prepared by deposition precipitation have been characterised and tested for the total oxidation of naphthalene. Two different precipitation methods were used to prepare the nano-crystalline ceria supports and it was observed that although both supports were active materials for naphthalene oxidation, ceria synthesized by homogeneous precipitation with urea was markedly more active than CeO 2 precipitated by carbonate. The addition of gold to both active CeO 2 catalysts resulted in different effects for the total oxidation of naphthalene. Gold addition promotes the naphthalene conversion to CO 2 when ceria is prepared by precipitation with carbonates, whilst the light off temperature is shifted towards higher temperatures when gold is added to ceria synthesized by the urea method. This behaviour has been related to a change in the support characteristics and a removal of the carbonate surface species, when gold is deposited onto the ceria support.

Total oxidation of naphthalene with high selectivity using a ceria catalyst prepared by a combustion method employing ethylene glycol

“…Indeed, these catalysts show a catalytic activity remarkably lower than CeO 2 (U) catalyst, according to its much higher specific surface area and lower crystallite size. Regarding to CeO 2 (P) catalyst, it has been previously reported [32] that the presence of carbonates contaminating the catalyst surface is negatively affecting its catalytic activity, so that Ce-EG catalysts exert higher activity although these catalysts present lower specific surface area and higher crystallite size.…”

Gold nanoparticles on metal oxide surfaces derived from n-alkanethiolate-stabilized gold nanoparticles; investigations of the adsorption mechanism and sulfate formation during subsequent thermolysis

“…In 1987, Haruta et al reported that when gold was deposited as nanoparticles on metal oxides, it was organic compounds (i.e., benzene, toluene, methanol, ethanol, 2-propanol, formaldehyde, acetone, etc.) from exhaust/waste gases [13][14][15][16][17][18][19]. Indeed, gold nanoparticles, when deposited on a variety of metal oxides, have been shown to exhibit a unique activity and selectivity for a number of reactions, such as low temperature oxidations, including the oxidation of CO, the catalytic combustion of hydrocarbons, the partial oxidation of hydrocarbons (such as propene epoxidation), the hydrogenation of carbon oxides and the reduction of NO [20][21][22][23].…”

Understanding of the oxygen activation on ceria- and ceria/alumina-supported gold catalysts: a study combining 18O/16O isotopic exchange and EPR spectroscopy

“…Among the reducible oxide supports, ceria was particularly investigated because of its capability to act as an oxygen reservoir by storing/releasing oxygen through a redox process which involves the Ce 4+ /Ce 3+ couple. Nanocrystalline ceria-supported gold catalysts were then studied in various catalytic reactions including the water-gas shift reaction [4,5], the VOC combustion [6][7][8][9][10], the selective oxidation of alcohol [11], the selective oxidation of CO in excess of H 2 (CO-PROX) [12], and the most investigated reaction remaining the low-temperature CO oxidation [13,14]. The morphology of Electronic supplementary material The online version of this article (doi:10.1007/s13404-013-0103-z) contains supplementary material, which is available to authorized users.…”