Temperature-sensitive Earth-abundant Catalysts for green Hydrogen production (TECHydro)

Africa’s total announced electrolyser pipeline capacity has reached 114 GW, with 61% of this tied to Sub-Saharan Africa [1].

In particular, South Africa is actively pursuing the hydrogen economy, which is projected to contribute 3.6% to GDP and create 380K jobs by 2050 [2]. The Kenyan Ministry of Energy also reported that green hydrogen is expected to improve agriculture by producing fertilisers, steel and chemicals in Kenya.

Among various green hydrogen technologies, alkaline water electrolysis (AWE) is considered the most mature for industrial scale-up [3]. However, its cold-start nature requires a ramp-up time of approximately one hour. This makes it challenging to integrate with renewable energy sources, which are difficult to predict.

Dr Dowon Bae’s group has already demonstrated a solar-thermal-boosted AWE, which produced 70% more hydrogen for the first hour than a conventional AWE [4]. Based on the group's previous advanced studies, Loughborough University shall conduct research which aligns with Africa's hydrogen energy strategies with leading universities in the South Sahara region.

The intended solution that Dr Bae’s team offers is to develop temperature-sensitive catalysts that exhibit a fast ramp-up rate. 

During the proposed period between 2025-2027, the EECS Lab team will lead a consortium of Loughborough University, the University of the Witwatersrand, and the Technical University of Kenya to discover non-noble catalyst combinations that exhibit high-temperature sensitivity, which can lead to highly efficient water oxidation and hydrogen production in the elevated temperature conditions, which is relevant to the actual operating environment of many South African countries. 

Under the hypothesis that temperature-dependent catalytic kinetics can be managed with transition metal oxide geometry, the research focuses on developing binary/ternary metal oxide catalysts and determining surface bonding structure change at elevated temperatures to reveal the underlying mechanism of temperature sensitivity.

Considering the project timeline (2 years), Ni, Co, and Mn will be employed as catalyst materials. The core tasks of the project are:

1. To establish cost-effective wet-chemical fabrication methods of binary/ternary metal oxide catalysts;
2. To provide a quantitative analysis of surface bonding structure under elevated temperatures;
3. To unravel the key links between compositional and bonding aspects of the catalysts and reaction kinetics with South African and Kenyan partners;
4. To demonstrate an AWE with developed catalysts in South Africa.

The advanced characterisation and system-level tests will be conducted at Loughborough University. The major catalyst development and fundamental characterisations will be conducted at the University of the Witwatersrand.

Along with the above-described experimental studies, atomic and electronic structure-related characteristics will be evaluated using first-principles calculations based on density functional theory (DFT) by the Technical University of Kenya (TU-K).

The proposed physics partnership project is anticipated to give rise to fresh perspectives on the temperature-sensitiveness of the catalyst for their application to green hydrogen production.

Moreover, the project will make a rigid bridge for close cooperation for further joint-research funding applications and staff exchange between African and UK partners. The quantitative goals of this collaborative project are as follows: 

1. Reduction of required cell voltage over 400 mV under 60°C gradient.  
2. Reduced ramp-up time by 50% compared to conventional alkaline water electrolyser (AWE). 

Alongside the above-listed quantitative goals, we aim to achieve the following key qualitative goals: 

1. Establishment of the physical and chemical property database of prepared binary/ternary catalysts.
2. Mapping of the reaction pathway for the developed metal oxide catalysts at various temperatures.
3. Long-term outdoor performance data on the degradation of catalytic electrodes.
4. The optimised compositional ratio of the catalyst using obtained field test results for enhanced stability.

We firmly believe the outcomes will set benchmarks for cost-effective hydrogen production that can operate more efficiently in Sub-Saharan African countries’ hot climates.

Kenya, like South Africa, is also exploring green hydrogen production to diversify its energy portfolio further, and as such, Kenya is expected to see a similar explosive demand for green-hydrogen-related jobs, similar to the South African government's job forecast.

Besides, the gender ratio between female and male researchers in the TECHydro project is well-balanced. Therefore, our project will directly contribute to gender equality by lowering the barriers for women in STEM.

Furthermore, the project will benefit green hydrogen industries (e.g., Fibretech, Oxford nanoSystems, etc.) with insights and expanded networks.

1. R. Pandey et al., Africa and Europe: green hydrogen economy, 2023.
2. President Cyril Ramaphosa: Second South African Green Hydrogen Summit, South African Government, 2023.
3. M. Chatenet et al., Water electrolysis, Chem Soc Rev, 2022, 51, 4583–4762.
4. D. Bae et al., Solar Thermal Integrated Alkaline Water Electrolyser for Fast Ramping Up, ECS Meeting Abstracts, I01-1841 (2024).