Energy Materials PhD: Catalyst Layers for Durable, Selective CO₂ Electrolysis

Energy Materials PhD: Catalyst Layers for Durable, Selective CO₂ Electrolysis

Quick Decision

This experimental PhD tests how ionomer chemistry, wettability and pore structure shape copper gas-diffusion electrodes during acidic CO₂ electrolysis, particularly C₂+ selectivity and durability. Controlled comparisons and mechanistic characterization suit applicants interested in electrochemical engineering, catalysis and materials interfaces. The application deadline is clear, but award pages disagree on the reference date and stipend year; confirm the entry-year package and international fee terms in writing.

Research Problem and Doctoral Work

What Is Unsolved and Why It Matters

Electrochemical CO₂ conversion can use renewable electricity to make chemicals. Alkaline electrolysers often reach high rates, but carbonate formation can consume CO₂ and lower carbon efficiency. Acidic operation may limit carbonate accumulation, while the proton-rich environment intensifies the competing hydrogen-evolution reaction (HER). Local conditions inside the catalyst layer can govern CO₂ access, water and ion movement, reaction intermediates and electrode degradation. The project addresses this coupled transport and chemistry problem.

Work, Methods, and Potential Outputs

The advertised plan is to fabricate gas-diffusion electrodes (GDEs) with well-defined Cu-based reference catalysts. Catalyst composition will be controlled while ionomer chemistry, wettability and porous architecture are systematically varied. The researcher will test high-rate acidic CO₂ electrolysis, quantify products, use electrochemical diagnostics and apply advanced characterization to connect interfacial transport and local conditions with multicarbon (C₂+) selectivity and electrode degradation. The stated aim is transferable microenvironment design principles.

This is a comparative experimental design; it does not specify cell geometry, electrolyte, target-product slate, operating range, characterization protocol, replication plan or durability threshold. It does not promise a particular yield or lifetime. Ask how the team will define a baseline and compare Faradaic selectivity, partial current, carbon utilization, energy use and stability under matched conditions.

Recent field literature illustrates why these variables matter. A 2025 Cu-GDE study reports 61% C₂+ Faradaic efficiency and 84% single-pass CO₂ utilization at 0.3 A cm−2 in pH 2 flow-cell conditions using a tailored polyionomer. A 2024 study reports 87% C₂+ Faradaic efficiency and a C₂+ partial current density of −1.6 A cm−2 with a superhydrophobic macroporous Cu electrode in its acidic setup. These are independent research results, not targets for this project; the materials, cell configurations and conditions differ.

School, Programme and Field Context

The project is listed in the University of Exeter's Department of Engineering for September 2027 EPSRC Doctoral Landscape Award entry. Exeter's Engineering research-degree page lists MPhil/PhD Engineering, Streatham Campus and full-time study; award 6014 supports up to 3.5 years full time. Exeter is the stated host and degree context. Professor Ifan Stephens at Imperial College London is a collaborating supervisor, and Henry Royce Institute is a research partner. The public material does not establish a joint degree or another awarding institution. Confirm the formal registration route and PGR training milestones in the offer.

Exeter reports QS World University Rankings 2027 overall rank 136 and THE 2027 overall rank =157. Its Engineering subject page reports 9th in the Complete University Guide 2027 for General Engineering. REF 2021's Engineering Unit of Assessment profile is 32% four-star, 60% three-star and 8% two-star. These measures provide university and subject context; none evaluates this specific project or its supervision.

Supervisor and Lab Assessment

Supervisor Research Directions

Dr Mengnan Wang's institutional profile lists CO₂ electrolysis, carbon utilisation, sustainable chemical manufacturing, electrocatalysis, interface/microenvironment engineering, porous-electrode design, operando characterization and scale-up. Her 2026 Royal Academy of Engineering Research Fellowship focuses on catalysts, electrodes and reactors for efficient, selective, durable and scalable acidic CO₂ electrolysers. Exeter's announcement links the wider programme to ethylene production, reaction-site control, new materials and simulations. This is a relevant research platform; the Fellowship's five-year term is separate from the studentship duration.

Professor Ifan Stephens is an Imperial Professor in Electrochemistry and leads the Interfacial Electrochemistry Group. His profile describes work combining electrochemical experiments, first-principles calculations and advanced characterization across electrocatalysis, including CO₂ reduction. The project names him as a collaborator for specialist mechanistic characterization and research visits. Routine supervision split and meeting cadence are not specified.

Recent Important Publications

These are independent field comparators, not papers attributed to the proposed supervisors. A directly matched recent publication from either named supervisor on this exact acidic Cu-GDE project was not verified in the public profiles reviewed.

• A 2025 JACS study combined amine, sulfonate and amphiphilic functions in a Cu-electrode coating. At pH 2 and 0.3 A cm−2, it reported 61% C₂+ Faradaic efficiency and 84% single-pass CO₂ utilization. This is a close comparator for the planned ionomer and local-environment work, though the coating and cell conditions are specific.
• A 2025 ACS Energy Letters study used distributed cation- and anion-exchange ionomers to manage the Cu interface. It reports about 40% ethylene Faradaic efficiency in strongly acidic conditions and extended total time under alternating on/off operation. The pulsed duty cycle and dual-ionomer architecture limit direct comparison with continuous operation.
• A 2023 Nature Catalysis study immobilised benzimidazolium groups in Cu ionomer coatings and reported more than 150 hours of acidic CO₂ reduction and 80±3% C₂+ Faradaic efficiency in its configuration. It shows how local water and cation management can affect performance; its chemistry is study-specific.
• A 2024 Nature Communications study engineered a superhydrophobic macroporous Cu GDE to improve gas access. Its reported acidic-electrolysis metrics support examining pore architecture and wettability, though the design is a particular electrode rather than a universal benchmark.
• A 2023 Nature Communications paper used surface hydroxide and in-situ Raman characterization to connect local surface conditions with C–C coupling and ethylene formation. This is relevant to the project's characterization logic, while the catalyst and run duration differ.
• A 2024 Journal of Materials Chemistry A study found that ionomer hydrophobicity and charged side chains influence Cu-electrode C₂+ performance in zero-gap electrolysers. Because it is not an acidic system, it motivates variables to test rather than predicting this project's results.

Lab, Resources, and Collaboration Environment

Henry Royce Institute lists a suite with scanning electrochemical microscopy and potentiostat, thin-film deposition, differential electrochemical mass spectrometry and Raman mapping. Its electrochemical-systems programme covers reaction and degradation mechanisms, testing, characterization and modelling. The facility page requires an access enquiry, so collaboration does not itself confirm a specific instrument booking. The project describes research-visit opportunities with Imperial and Royce, an expected cohort of three to four complementary PhD researchers and industrial links including Johnson Matthey; visit frequency, company responsibilities and budgets remain unspecified.

Funding, Application, and Living Cost

Award 6014 describes up to 3.5 years full time, an index-linked stipend currently £21,805 per year at the 2026/27 rate, Home tuition and £5,000 RTSG over 3.5 years. UKRI's 2026/27 minimum stipend is also £21,805, with a £5,238 fee level. Since Exeter's summary row labels £21,805 a 2027/28 rate, confirm the amount that will apply from September 2027 in the written offer.

The university says it covers the Home/international tuition difference for successful eligible international awardees. Central DLA guidance limits international fee-status awards to up to 30% of the cohort and applies complex residence rules. It says visa, healthcare surcharge and moving costs are not covered. Check residence/fee status and the complete net support package early.

Exeter estimates basic living costs for a single student in Exeter or Cornwall at £1,300–£2,000 per month. Annualizing £21,805 gives about £1,817/month: roughly £517 above the low estimate or £183 below the high estimate before one-off arrival costs, housing choices or dependants. This is a planning comparison, not an individual budget.

The application deadline is midday Tuesday 8 December 2026. The 6014 page says references are due 8 January 2027, whereas central DLA guidance gives 15 February 2027. Use the earlier date as the safe plan and ask PGR Admissions to confirm. The project page gives likely interviews on 15–24 February 2027; central guidance also contains a stale sentence referring to 2026 interviews/outcomes. Both pages list a personal statement, CV, transcripts, two references and English evidence where applicable; documents must be in English, with certified translations of qualifications when relevant. Each selected project needs a separate application, up to three, and a preferred project should be named.

Applicant Fit and Preparation

Required Background and Skills

The project description names Chemical Engineering, Chemistry, Materials Science and closely related fields. The DLA baseline expects a First or Upper Second UK honours degree or equivalent in an appropriate science or technology area; a Lower Second may be considered with a Master's degree or significant relevant non-academic experience. English-language evidence applies where required. Prior electrochemistry, electrocatalysis, materials synthesis or characterization is advantageous but explicitly not essential.

Preferred Experience and Suggested Preparation

A strong application can show relevant research or laboratory experience, careful experimental controls, quantitative data handling and interest in connecting materials interfaces with device performance. Preparation in electrochemical diagnostics and GDE characterization may help at interview, but these are not extra entry requirements. Candidates seeking a primarily computational PhD or work focused mainly on discovering new catalyst compositions should clarify the experimental, microenvironment-led scope.

Career Paths and Market Context

Training in experimental electrochemistry, catalyst-layer and porous-electrode design, quantitative product analysis, materials and process engineering could transfer to electrochemical-device or electrode R&D, materials/process engineering, clean-energy and chemical-technology development and scale-up, industrial decarbonisation, CCUS-adjacent work, and related research or technical roles. A UK government clean-energy skills assessment cites potential for up to 50,000 jobs by 2050 across the whole CCUS sector and its supply chains; this is not a forecast for acidic CO₂ electrolysis. The National Careers Service lists a broad chemical-engineer pay range of £34,000–£65,000, which is not a PhD-specific salary or placement estimate. The niche market for acidic CO₂ electrolysis is not quantified, and neither these pathways nor broader sector figures guarantee employment after graduation. (Clean-energy skills assessment, National Careers Service: chemical engineer)

Next Actions and Questions to Verify

Before Applying

1. Ask Exeter whether 6014 references are due 8 January or 15 February 2027; plan for 8 January unless confirmed otherwise.
2. If applying internationally, check residence criteria, cohort limit and how fee-difference coverage is documented.
3. Confirm the 2027/28 indexed stipend and whether any project-specific proposal is required beyond the stated application documents.
4. Submit by midday 8 December 2026 with complete supporting documents.

At Interview

• Which Cu catalyst, reactor/electrolyte configuration and operating point form the baseline?
• Which products and metrics define success: Faradaic selectivity, partial current, carbon utilization, energy efficiency or lifetime?
• How will ionomer, wettability and porous architecture be varied with controls and replication?
• Which Imperial/Royce methods and visits are confirmed, and who funds travel/access?
• How will Dr Wang and Prof Stephens divide day-to-day supervision, and what is the practical role of industrial collaborators?

Before Accepting an Offer

• Confirm start date, funded duration, indexed stipend, tuition coverage, research-cost budget and international conditions.
• Confirm Exeter registration, PGR milestones and expected cross-site travel or training.
• Ask for the project's milestones and durability criteria to judge the scope against the funded period.

Evidence and Sources

Project and programme

• Official project description: Engineering Catalyst-Layer Microenvironments for Selective and Durable Acidic CO₂ Electrolysis
• EPSRC DLA Department of Engineering PhD Studentships, award 6014
• Important information about EPSRC Doctoral Landscape Award studentships
• Finding a PhD research project: EPSRC DLA 2027
• Engineering PhD and research degrees

School, supervisors and facilities

• Research | Engineering | University of Exeter
• University of Exeter rankings
• University of Exeter REF 2021 results
• Mengnan Wang profile and research interests
• Dr Mengnan Wang – Research Fellowships 2026–2031
• Exeter engineer awarded Royal Academy Fellowship
• Professor Ifan Stephens – Imperial College London
• Ifan Stephens – publications
• Electrochemistry Research Suite – Henry Royce Institute
• Electrochemical Systems – Henry Royce Institute

Research papers and field context

• Catalyst–electrolyte interface engineering propels progress in acidic CO₂ electroreduction
• Chemostructurally Stable Polyionomer Coatings Regulate Proton-Intermediate Landscape in Acidic CO₂ Electrolysis
• Carbon Efficient CO₂ Interfaces in Acid through Ion Management Channels
• Cationic-group-functionalized electrocatalysts enable stable acidic CO₂ electrolysis
• Gas diffusion enhanced electrode with ultrathin superhydrophobic macropore structure for acidic CO₂ electroreduction
• Surface hydroxide promotes CO₂ electrolysis to ethylene in acidic conditions
• Benchmarking ionomers for CO₂ electroreduction to multicarbon products in zero-gap electrolysers

Funding, costs and careers

• Guidance for training grant holders – UKRI
• Budgeting for international students – University of Exeter
• Assessment of the clean energy skills challenge – GOV.UK
• Chemical engineer – National Careers Service