Bifunctional Hybrid Electrocatalysts for Oxygen Evolution and Oxygen Reduction Reactions

Lead Research Organisation: Queen Mary, University of London
Department Name: Sch of Engineering and Materials Science

Abstract

This project aims to create transition metal perovskite/Nitrogen-doped Carbon electrospun nanofibres as alternative cost-efficient bifunctional electrocatalysts to replace noble metals for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) in energy conversion (PEM fuel cells and water electrolysers) and storage (metal-air batteries) devices. At the same time, I will develop new in situ studies that will allow a deeper understanding of the structure-property relationships allowing for further optimisation.
The search for green alternative sources of energy is of great importance for our current society. In order to battle increasing greenhouse gases and global warming created by the use of fossil fuels, and to meet the UK's 2050 climate change targets, we need to develop new technologies that allow researchers to tackle this problem. Some of these alternatives include fuel cells, solar cells, batteries, supercapacitors and water electrolysers. OER and ORR are key processes taking place in most of these technologies and will be the focus of this project. The high cost of the noble metal catalysts employed in energy conversion and storage devices is one of the major drawbacks to their full development and exploitation. There are many reports new materials that can overcome state-of-the-art limitations at an acceptable cost. However, not much research has been done to understand the effect of nanostructuring, hybridisation between various electrochemically active materials and understanding the structure-property relationships to allow an improved performance.
In this project, I will design hybrid materials combining already known transition metal perovskite electrocatalysts with nitrogen-doped carbons electrocatalysts using the electrospinning technique. These new hybrid nanostructures will be characterised using state-of-the-art techniques. I will also design in operando studies combining structural and property coupled measurements. The electrocatalytic activity of perovskites is thought to be due to the presence of oxygen vacancies in their structure. By combining Raman spectroscopy and OER and ORR measurements, we will be able to monitor the changes in the oxygen vacancies of the perovskites (detected by Raman spectroscopy) as their electrochemical performance is evaluated. A similar approach will be developed using X-ray computed tomography, which will provide invaluable information about the complex structures and interactions involved in the catalytic process at the different structural levels of organisation and integrated within real devices. This will be correlated with the electrocatalytic activity of N-doped carbon materials studied by X-Ray Adsorption studies and the synergy between these two electrocatalysts understood. This will lead to a better understanding of the parameters influencing the activity of these materials in relation to their structure and also to the device environment and will facilitate a better electrode engineering.
This project will be conducted at the Materials Research Institute (MRI), Queen Mary University of London (QMUL). The MRI brings together a range of expertise with different schools including Engineering and Materials, Physics and Astronomy, Biological and Chemical Sciences, and Dentistry, providing a platform to support interdisciplinary materials research. I maintain a close collaboration with the Electrochemical Innovation Lab (Chemical Engineering Department, UCL) which will provide access to X-ray computed tomography and industrial links to test the new materials at scaled-up dimensions. Coupled structure-property studies will be carried out in collaboration with Dr. Ozlem Sel and Dr. Ivan Lucas, from Laboratoire Interfaces Systemes Electrochimiques (LISE, CNRS, Paris, Sorbonne Universites). An internal collaboration with Prof. Titirici group at MRI-QMUL working on N-doped carbon electrocatalysis will complement these collaborations.

Planned Impact

This project will have great impact on society and economy through the design of oxygen electrocatalysts for sustainable, energy-efficient devices.The UK Energy White paper and the first RCUK Review of Energy evidence the importance of this area for UK.Important benefits to society can be foreseen since this project will contribute to reduce the cost of the materials used in energy technologies.Specifically,I will research alternative materials to noble metals for oxygen evolution reaction (OER) and oxygen reduction reaction (ORR).The approaches proposed here to design and prepare OER/ORR electrocatalysts using electrospinning will lead to a potential step-change in energy conversion and storage technologies, with huge associated impact.A project of this size cannot be expected to directly impact global energy policy in isolation.However,by seeking collaborations with academics and industry, this research aims to contribute to solve energy problems facing the world, through designing and engineering hybrid electroactive materials for energy devices at an acceptable cost.
1)Societal impact:This project will increase community consciousness about the importance of the contribution of society to reduce gas emissions by adopting environmentally friendly habits.Actions to engage general public will involve:(i)lectures and workshops at schools to provide teachers with exciting educational materials they can use, to make them aware of renewable energy alternatives to fight global warming;(ii)to involve undergraduate students in energy research by organising lab demonstrations on how a battery,fuel cell or water electrolyser works preceded by a short theoretical explanation and their benefit;(iii)to disseminate results in journals directed to a general audience.Experiments and workshops will be explained in a didactic way through series of demonstrations,internet and public lectures.Some of the funding allocated to Impact (£8,000) will be used to support these activities.Egagement activities will be conducted through workshops and interactive seminars.QMUL has created a Centre for Public Engagement,which will provide advice and support for engagement activities.
2)Economic impact:This project will involve a proof of concept stage,testing of the materials in PEM fuel cell,PEM water electrolyser,and metal-ion battery devices,operating in real world conditions.To achieve this, the close collaboration I keep with the UCL Electrochemical Innovation Lab and industrial partners (ITM Power and PV3) will be extremely valuable and will be a pathway to impact.This will be very useful to obtain inputs on performance and stability metrics to target and planning scale-up approaches.Additional industrial contacts will be made through industry bodies such as the UK Hydrogen and Fuel Cell Association (http://www.ukhfca.co.uk/) and KTNs.Additionally,funds could be available through the Innovate UK projects (https://projects.innovateuk.org/),based on the commercial promise of my new materials.STFC also funds different projects (http://www.stfc.ac.uk/funding/) and covers costs of travel and research developed at national facilities.
3)Academic impact:Results will be published in scientific journals and conferences.I will join the Supergen network to promote collaborations.The impact of publications and technology advances will be promoted by the use of media press releases,and use social media to disseminate research news.This project will link chemistry syntheses,processing and characterisation techniques along with engineering and testing of energy conversion and storage devices,combining joint efforts from which researchers and students can benefit.PhD,master students,and postdoctoral researchers will benefit from a multidisciplinary research taking place at the interface between chemical engineering,chemistry and material science to develop new relevant materials for replacing noble metals in current energy conversion and storage technologies.

Publications

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Description Our project focuses in the development of freestanding electrospun oxygen bifunctional electrocatalysts for application as electrodes in energy storage technologies, such as metal-air batteries and regenerative fuel cells. So far, we have successfully electrospun a N-doped carbon / NiFe2O4 oxygen electrocatalyst using a coaxial needle, which allows us to electrospin two different solutions at the same time, creating a core/shell fibre-like structure. To the best of our knowledge, this is the first time this has been achieved, which is already positive outcome, in terms of materials synthesis and processing. Unfortunately, we still need to optimise the NiFe2O4 loading and homogeneity onto the N-doped carbon fibres, but we are confident that we will achieve an even coverage. Now, we are in the process of optimising the processing parameters to achieve the desired electrochemical performance and finally test it in a real device. During this time, my group has grown thanks to additional funding, and now consists of six PhD students and one postdoc, some of them also doing related-research.
Exploitation Route This project is expected to have great impact on society and economy through the design of oxygen electrocatalysts for sustainable, energy-efficient devices. We are looking into designing activities to engage with the community. Some of the actions involve:(i) workshops at schools to provide teachers with educational materials they can use, organising lab demonstrations on how a battery, fuel cell or water electrolyser works preceded by a short theoretical explanation. We have already participated (October 2018) in the Year of Engineering, with a stand at the London Science Museum for the Family Fair (ReCharge stand). There we explained how batteries work, and made batteries out of lemons and other fruits and vegetables. Out stand was very successful. We will continue designing this type of activities for general audience. Regarding academic impact, we have already disseminated the preliminary outcomes of the grant in UK and European meetings, and published several papers and will continue doing so as the project moves forward. We will also get in contact with our industrial partners as soon as we have optimised our materials and conducted initial real cell tests in the laboratory.
Sectors Communities and Social Services/Policy,Education,Energy,Manufacturing, including Industrial Biotechology

 
Description Collaboration with Indonesian partner in developing new carbon - based materials for energy storage 
Organisation Hasanuddin University
Country Indonesia 
Sector Academic/University 
PI Contribution As a result of the EPSRC First Grant, I was able to get involved in a workshop for Early Career Researchers, focused on energy materials. There I made contact with Dr. Zakir, and others, and started a collaboration. We signed a MoU between QMUL and Hasanuddin University. My contribution consisted in providing the know-how and the infrastructure at QMUL to develop carbon materials for energy applications. Dr. Zakir came to QMUL and spent a month developing new materials to be tested back in Indonesia. This collaboration was really successful and resulted in a new publication in a conference (please see https://iopscience.iop.org/article/10.1088/1742-6596/979/1/012024/meta).
Collaborator Contribution My partners developed the tests back in Indonesia and attended the conference series where our proceeding was published.
Impact The disciplines involved were: Materials Science and Chemical Engineering One proceeding is the outcome of this collaboration: https://iopscience.iop.org/article/10.1088/1742-6596/979/1/012024/pdf So far, we have applied two times to the Newton Institutional Links without success, but we will keep trying to apply for funding to continue this collaboration.
Start Year 2017
 
Description Collaboration with Sorbonne University to study electrocatalyst mechanisms using electrochemical quartz crystal microbalance 
Organisation Sorbonne Universit├ęs
Country France 
Sector Academic/University 
PI Contribution I have developed the new electrochemical materials to conduct a study supported by STFC Battery travel grant. These materials are C-based electrochemically active compounds prepared within the framework of my EPSRC First Grant
Collaborator Contribution My collaborators at the Laboratoire Interfaces et Systèmes Electrochimiques CNRS - Sorbonne Université, are experts in the use of electrochemical quartz crystal microbalance (EQCM) to investigate multiple reaction mechanisms. I have synthesised carbon electrodes with different surface functional groups and morphological features. EQCM experiments have been carried out at LISE also in a three-electrode configuration. In a further step, an advanced mode of QCM (coupled to impedance spectroscopy, QCM-EIS) will be used for the ionic transfer and transport properties of the vanadium ions. Finally, the electrodes with optimised surface functions based on the electrochemical study results will also be tested in a full-cell system. To the best of our knowledge, this is the first systematic study of the redox and diffusion processes taking place in a flow battery using electrochemical microbalance and we believe it will have a great impact in the field.
Impact Disciplines involved in this project are Chemistry, Materials Science and Physical Chemistry. We are in the process of writing a paper (invited ChemPlusChem) with some preliminary results from this collaboration. More publications are pending, too.
Start Year 2017
 
Description ReCharge at the London Science Museum 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact The demonstration consisted on an all-vanadium redox flow battery system connected to a potentiostat. The set up showed how to charge and discharge a redox flow cell, using vanadium ions as the redox-active species. The advantage here is that the vanadium species show different colour depending on their oxidation state, so a visual representation of the state of charge of the system is intuitive and easy to follow. In discharge mode, our idea is to connect the battery to a series of LEDs forming the word Redox Flow Battery, and the battery is scaled so that charging occurs on the order of minutes, producing the colour change while visitors to the stand are told how the system works. Wider discussion about clean energy, energy storage and the link between electronic structure and colour also took place.
Year(s) Of Engagement Activity 2018
URL https://www.sems.qmul.ac.uk/news/4883/we-are-engineers-family-festival-at-the-science-museum-this-we...