Identifying species controlling activity and stability of metal oxide electrocatalysts for green hydrogen production
Professor James R Durrant
Imperial College London
Green hydrogen production from proton exchange membrane (PEM) catalysts is the most amenable technology for hydrogen production from renewable electricity, based on the UK Government’s Hydrogen Strategy, 2021. However, the fundamental bottleneck in scaling up PEM electrolysis to the terawatt level is discovering catalysts for the anodic water oxidation reaction, that are active and stable at low pH and highly oxidizing conditions and do not rely on high loadings of precious metals such as iridium. Development of more active and stable catalysts requires fundamental understanding about the active sites and reaction mechanisms driving catalysis and degradation.
In this project, we will investigate a range of oxide based electrocatalysts (including those provided by BASF) using;
(i) operando time-resolved optical spectroscopy (Durrant group) to determine the density and kinetics of redox active centres as a function of applied potential,
(ii) ultra high sensitive operando mass spectrometry (Stephens group) to probe the degree of lattice oxygen participation and gas-phase degradation products under industrially relevant current densities and
(iii) post-mortem inductively coupled plasma mass spectrometry to determine the amount of dissolved species in solution.
Based on this mechanistic understanding, we can rationally design next-generation catalyst chemistries with minimal loading of precious metals that can not only result in improved efficiencies but can also withstand the harsh environments experienced under operating conditions, by eliminating the sites most prone to dissolution.
• Operando time-resolved optical spectroscopy in the Durrant group will be used to measure the evolution of redox active states as a function of potential and their kinetics for water oxidation.
• Electrochemical mass spectrometry in Stephens’ group using 18O-labeled electrolyte will be used to measure the degree of lattice oxygen participation during the water oxidation reaction as well as the presence of any gas-phase degradation products.
• Inductively coupled mass spectrometry will be used to measure the amount of dissolved ions in solution following electrochemical measurements.
Complementary mechanistic information provided by these techniques will be critical for project completion.
For information on how to apply for this project please visit cdt-acm.org/phd-opportunities
I really enjoyed my time as a member of the CDT-ACM. It provided the opportunity to gain experience with a wide range of materials characterisation techniques and to engage with the wider research community by participating in conferences and Outreach events.