Physico-chemical and catalytic activity comparaison in the oxidation reactions, between two series of Ag/CeO₂ solids, prepared by two different methods : Impregnation and Deposition-precipitation
type: Dataset
description: Ceria is a well known support in the world of catalytic oxidation reactions. Adding transition metals tend to enhance the catalytic activity. Silver was used in our work, and was added using two different preparation methods : the impregnation (Imp) and the deposition-precipitation (DP). The first known by the formation of different particles size on the surface of the support, whereas the second is known by the formation of nanoparticles with a good dispersion on the surface and in the bulk of the support. Two catalysts series x%Ag/CeO₂(Imp) and x%Ag/CeO₂(DP) (where x is the weight percentage of silver over ceria) were prepared in order to compare their physico-chemical properties and afterward their catalytic performances in three different oxydation reactions. The catalysts were characterized using BET, XRD, EPR, DSG-TG, XPS, UV and TPR techniques. XRD showed on both series the formation of Ag⁰ particles for the catalysts with high weight percentages. The sizes of these particles are larger in the (Imp) solids compared to the (DP) ones. Beside of these particles, the formation of Ag⁰ nanoparticles was confirmed by the plasmonic resonance in the UV technique. The nanoparticles are spherical in the (DP) solids and half spherical (misshaped) in the (Imp) solids. Three oxidation states were found in the (Imp) catalysts : Ag⁰, Ag⁺ et Ag²⁺ compared to only two in the (DP) : Ag⁰ et Ag⁺. The nitrate present in the AgNO₃ (silver precursor) during the calcination might be the reason of the formation of the Ag²⁺. That is not the case for the (DP) solids. The two isotopes for Ag²⁺ (¹⁰⁷Ag²⁺ and ¹⁰⁹Ag²⁺) were identified with the EPR technique. This result is considered as original and very important. Afterward, the catalysts were tested in the total oxidation of the propylene, carbon monoxide and carbon black. The catalytic results were unexpected and oppose the literature results. (Imp) catalysts showed a higher activity than the (DP) in all the reactions. The catalytic perfo…
landing page: https://theses.hal.science/tel-00983419
identifier: NNT: 2013DUNK0345
keyword: argent
keyword: catalytic-oxidation
keyword: ceria
keyword: cerine
keyword: chimothechemical-sciencesother
keyword: comparaison-physico-chimique
keyword: deposit-haste
keyword: depot-precipitation
keyword: impregnation
keyword: infoeu-reposemanticsdoctoralthesis
keyword: oxydation-catalytique
keyword: physico-chemical-comparison
keyword: silver
keyword: theses
issued: 2026-05-05T13:12:13.192168
modified: 2026-05-05T13:12:13.192174
language: fr
contact point: Organization
  fn: CCSD

test_moissonnage_selune
type: Agent

Physico-chemical and catalytic activity comparaison in the oxidation reactions, between two series of Ag/CeO₂ solids, prepared by two different methods : Impregnation and Deposition-precipitation
type: Distribution
format: HTML
access URL: https://theses.hal.science/tel-00983419
issued: 2026-05-05T13:12:13.195805
modified: 2026-05-05T13:12:13.175647