Skip to Main content Skip to Navigation
Theses

Synthèse de films nanocomposites Ag/YSZ, Ag/CGO & Ag(Cu)/CGO par pulvérisation cathodique magnétron réactive pour l’électrocatalyse de l’éthylène en oxyde d’éthylène

Abstract : Ethylene oxide (EO) is an essential building block for the chemical industry. It is produced by the ethylene epoxidation reaction over a silver-based catalyst. Nevertheless, to achieve high selectivity, industrial processes use chloride additives in the gas phase and alkaline moderators on the catalyst. The aim of this study is to increase EO selectivity without chloride additives thanks to Ag/fluorite oxides electrocatalysts synthesized by reactive magnetron sputtering and incorporated in a 3-electrodes configuration cell designed for electrochemical promotion of catalysis, EPOC. Three porous systems (Ag/YSZ, Ag/GDC, Ag(Cu)/GDC) have been synthesized by reactive magnetron sputtering. Ag/YSZ 4 Pa 25 mA nanocomposite thin film exhibits a botryoidal microstructure characteristic of silver segregation inside the YSZ matrix. Ag/GDC 4 Pa 70 mA nanocomposite thin film exhibits a brain like-morphology with open nanoporosities. Ag(Cu)/GDC 4 Pa 70 mA nanocomposite thin film consists of multi-phase hydrophobic entropic nanowires. During catalytic tests under ethylene epoxidation conditions in reducing medium, Ag/GDC 4 Pa 70 mA showed the maximum EO selectivity of 16.55 % at 220 °C and, under polarization, selectivity boost of 2.78 % occur without the appearance of NEMCA effect.
Complete list of metadata

https://hal.univ-lorraine.fr/tel-03284802
Contributor : Thèses Ul <>
Submitted on : Monday, July 12, 2021 - 8:06:08 PM
Last modification on : Wednesday, July 14, 2021 - 3:35:20 AM

File

DDOC_T_2020_0257_GILBERT.pdf
Files produced by the author(s)

Identifiers

  • HAL Id : tel-03284802, version 1

Citation

Benjamin Gilbert. Synthèse de films nanocomposites Ag/YSZ, Ag/CGO & Ag(Cu)/CGO par pulvérisation cathodique magnétron réactive pour l’électrocatalyse de l’éthylène en oxyde d’éthylène. Science des matériaux [cond-mat.mtrl-sci]. Université de Lorraine, 2020. Français. ⟨NNT : 2020LORR0257⟩. ⟨tel-03284802⟩

Share

Metrics

Record views

20

Files downloads

23