The Power of Interfaces: Fundamentals for Solid State Devices
The joint SOIFIT-Harverstore meeting was held at the historic Royal Society in London on10-11th March 2020.
The research interests of Skinner research group centre on the properties and structures of ion-conducting oxides, with emphasis on the identification and characterisation of new materials using in- situ high-temperature techniques such as x-ray and neutron powder diffraction techniques, secondary ion mass spectrometry and low energy ion scattering. This work has potential applications in the development of solid oxide fuel cell, electrolysis and permeation membranes and more have been identified as having application in the field of novel solid-state gas sensors.
Our Latest Publications
Here, we investigated the high temperature structural properties of the LaNb1–xWxO4+d (x = 0.04–0.16) family, which is a structural analogue of hyper-stoichiometric CeNbO4+d.
Low-Temperature Exsolution of Ni–Ru Bimetallic Nanoparticles from A-Site Deficient Double Perovskites
A-site deficient double perovskite oxides, La2-xNiRuO6-δ (x = 0.1 and 0.15), are designed and subjected to low-temperature reduction leading to exsolution. The reduced double perovskite materials are shown to exsolve nanoparticles of 2–6 nm diameter during the reduction in the low-temperature range of 350–450 °C. The onset of the exsolution process is found to be within the first few minutes of the reduction reaction. In addition, the area-specific resistance of the electrode layers is found to decrease by 90% from 291 to 29 Ω cm2, suggesting encouraging prospects for these low-temperature rapidly exsolved Ni/Ru alloy nanoparticles in a range of catalytic applications.
Theory of the Electrostatic Surface Potential and Intrinsic Dipole Moments at the Mixed Ionic Electronic Conductor (MIEC)-gas Interface
Using the theory of the electrostatic potential at the MIEC-gas interface as an electrochemical driving force, charge transfer at the ceria-gas interface has been modelled based on the intrinsic dipole potential of the adsorbate. This model gives a physically meaningful reason for the enhancement in electrochemical activity of a MIEC electrode as the steam and hydrogen pressure is increased in both fuel cell and electrolysis modes. This model was validated against operando XPS data from previous literature to accurately predict the outer work function shift of thin film Sm0.2Ce0.8O1.9 in a H2/H2O atmosphere as a function of overpotential.
Non-equilibrium thermodynamics of mixed ionic-electronic conductive electrodes and their interfaces: a Ni/CGO study
In this work, the effects of non-equilibrium on the electrostatic surface potential have been studied and its influence over electrode kinetics were evaluated . By investigating two phase (2PB) and three phase boundary (3PB) reactions at the Ni/Ce1−xGdxO2−δ (Ni/CGO) electrode, it is demonstrated that the driving force for coupled ion-electron transfer is held at the CGO–gas interface for both reaction pathways. The rate of coupled ion-electron transfer via the 3PB scales with the availability of free sites on the metallic surface was also determined, revealing a Sabatier-like relationship with regards to the selection of metallic phases. These findings therefore provide an insight into the design of future electrode structures for a range of electrochemical devices.