Energy-filtered environmental transmission electron microscopy for the assessment of solid–gas reactions at elevated temperature: NiO/YSZ–H2 as a case study

Abstract

A novel approach, which is based on the analysis of sequences of images recorded using energy-filtered transmission electron microscopy and can be used to assess the reaction of a solid with a gas at elevated temperature, is illustrated for the reduction of a NiO/ceramic solid oxide fuel cell anode in 1.3mbar of H2. Three-window elemental maps and jump-ratio images of the O K edge and total inelastic mean free path images are recorded as a function of temperature and used to provide local and quantitative information about the reaction kinetics and the volume changes that result from the reaction. Under certain assumptions, the speed of progression of the reaction front in all three dimensions is obtained, thereby providing a three-dimensional understanding of the reaction.

Methods for Calibration of Specimen Temperature During In Situ Transmission Electron Microscopy Experiments

“…Figure 3 shows examples of metals and alloys that have been melted previously in a TEM (Baker & Harris, 1972; Wang et al, 1998; Walsh et al, 2009; Yonezawa, 2009; Asoro et al, 2010; Ida et al, 2010). Due to the relatively high melting point of most metals, there are few pure metals to use for calibration in the temperature range 400–900°C where many interesting reactions have been studied by in situ TEM (Helveg et al, 2004; Diaz et al, 2012; Peng et al, 2012; Jeangros et al, 2016). If the experiments are conducted in the presence of reactive gases, it is important to choose materials that do not react with the gas phase to change the chemical state of the element.…”

Addressing planar solid oxide cell degradation mechanisms: A critical review of selected components

“…Faes et al 143 . and Jeangros et al 79,142 . explained the reduction and oxidation kinetics of Ni(O) particles as well as of Ni(O)‐YSZ cermet through a series of detailed, systematic and related energy‐filtered TEM (ETEM) studies (see Figure 5).…”

“…Faes et al 143 and Jeangros et al 79,142 explained the reduction and oxidation kinetics of Ni(O) particles as well as of Ni(O)-YSZ cermet through a series of detailed, systematic and related energy-filtered TEM (ETEM) studies (see Figure 5). Using ETEM on a sequence of images as a function of temperature, the speed of progression of the NiO-YSZ reduction reaction front in all three dimensions was obtained, providing a 3D monitoring of the reaction.…”

Visualization of the structural transformation of NiO/YSZ/BZY nanocomposite particles using in situ gas environmental transmission electron microscopy

“…ETEM, equipped with a specialized sample holder that can provide controlled temperatures and gaseous environments within the specimen chamber, is ideally suited for investigating dynamic gas-solid reactions with ultra-high spatial resolution in catalysts [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] and fuel cell materials. [20][21][22][23] Nowadays, this advanced setup allows researchers to precisely control the experimental conditions and observe the intricate processes occurring at the atomic and molecular scales.…”