Metal-organic frameworks, or MOFs, are crystals that are mostly empty space. A teaspoon of MOF granules has the internal surface area of two tennis courts, and chemists can tune the pores to grab one gas and let the rest pass. That makes them useful for pulling CO2 out of a flue, upgrading biogas to biomethane, storing gas at lower pressure and harvesting drinking water from dry air.
The science won the 2025 Nobel Prize in Chemistry, shared by Susumu Kitagawa, Richard Robson and Omar Yaghi. The hard part has been the factory. For most of the field's history MOFs were made in batches over many hours and sold by the gram or the kilogram. Carbon capture is measured in tonnes.
Promethean Particles exists to close that gap. Its founder, Professor Ed Lester, is a chemical engineer at the University of Nottingham who spent the early 2000s on a stubborn problem: making particles continuously by mixing superheated water with a cold metal-salt solution. His early reactors kept blocking. The fix was to stop fighting the physics. Superheated water is lighter than the cold feed, so his counter-current reactor sends it down from the top while the cold solution is pumped up from below. The two meet in a controlled swirl, particles form in a fraction of a second and flow straight out. The design was patented in 2004, and Lester spun the company out of the university in late 2007.
For its first decade the company made nanomaterials for coatings, electronics and textiles, and growth was slow. Its share price moved from £1.00 in 2012 to £1.10 through 2015 to 2017 and £1.20 in 2022. Some deep-science businesses take that long to find the market that fits the technology. In 2020 it turned the reactor to MOFs. Ordinary shares priced at £1.20 in February 2022 put the company's pre-money valuation at about £4.9m, when it had 11 staff and had not yet run an industrial trial.
In July 2024 the £8m Series A, led by Mercia Ventures and Aramco Ventures, priced new shares at £1.82, a pre-money valuation of about £9.8m. That's 52% more per share than the 2022 price, in a little over two years.
University research rarely fails on the idea. It fails in the years between a lab result and a customer, when the work is too applied for a research grant and too early for most investors. Promethean spent more than a decade in that gap.
The University of Nottingham has backed it the whole way. It took founding shares at the spin-out, invested again in 2017 and in the 2020 to 2022 rounds, put £125,000 into the Series A and added to its holding further in 2024. It is one of the company's largest shareholders. Nottingham Technology Ventures, the university's venture arm, now selects the spin-outs that University of Nottingham EIS Fund I will invest in.
The turn to MOFs reset the company's buyers. Nanomaterials had been a long list of small markets; MOFs gave Promethean a short list of large ones, with carbon capture at the top.
The first proof came at Drax Power Station in 2022. Promethean, the university and Drax ran a two-month pilot capturing CO2 from biomass power using MOF sorbents rather than the liquid solvents most capture plants use. It was a trial, not a contract, but it put the material in an industrial flue gas rather than a lab rig.
The Series A followed in 2024, raised to build a larger plant at Genesis Park in Nottingham, which the company believes is the world's largest continuous MOF manufacturing facility. Paul Capell, a former main board director at United Utilities, became chair in February 2025, and Paul Denney joined that October as the company's first chief financial officer.
The milestone that mattered most came in November 2025, a month after the Nobel announcement. Promethean manufactured and shipped four tonnes of MOF to a customer in continental Europe for a gas storage application.
In July 2026 Ahbstra launched the ARK, an atmospheric water harvester built on Promethean's ProMOF 3100 material and rated at up to 500 litres of drinking water a day in hot, dry climates.
Order volumes, plant capacity and product performance figures on this page are as reported by the company or its customers.
The open question is which market buys in volume first. Promethean can make MOFs by the tonne; carbon capture, gas storage and water harvesting each have to show the material pays for itself at scale before orders follow.
The company's stated priorities are:
Scale: expand production to meet demand for MOF materials
Deploy: move from pilots to commercial projects in carbon capture and climate technology
Partner: sign new commercial partnerships in gas storage, gas separation and water harvesting
That is the company's plan, not a forecast.
The University of Nottingham holds about 15% of Promethean's ordinary shares, plus preference shares from the 2020 to 2022 rounds. Its founding shares weren't bought at a round price, so there is no per-share multiple to report for the university.
The filed prices show how the company has been valued. A private investor who bought at £1.10 in 2015 to 2017 holds shares last priced at £1.82 in July 2024, about 1.65 times their entry price per share, before fees and unrealised. Over the same period the company's pre-money valuation rose about 4.6 times, from £2.1m to £9.8m; the difference is dilution, because new shares were issued at every round. These are private round prices, not a market price, not a return on anyone's capital, and they can fall as easily as they have risen.
Round | Price per share | Pre-money valuation | Who invested |
March 2012 | £1.00 | About £0.9m | Seed investors and private investors |
2015 to 2017 | £1.10 | About £2.1m to £3.0m | Private investors, East Midlands Early Growth Fund, University of Nottingham |
2020 to 2022 | £1.20 (ordinary) | About £4.9m | Midlands Engine Investment Fund, East Midlands Early Growth Fund, University of Nottingham, private investors |
July 2024, Series A | £1.82 | About £9.8m | Mercia Ventures and Aramco Ventures (leads), Midlands Engine Investment Fund, University of Nottingham, East Midlands Early Growth Fund, TSP Ventures, private investors |
The funding record. Source: Companies House share allotments and confirmation statements; pre-money valuations are calculated from the ordinary shares in issue before each round at that round's price, excluding preference shares and options. Series A shares are a separate class with their own rights, so prices across classes aren't like for like. Institutional money in 2020 to 2022 came in mainly as preference shares with ordinary shares attached. About £1.1m of the £8m Series A converted from an earlier instrument at £1.456, a 20% discount to the round price. Not a market price.
Promethean took 17 years to reach its Series A, and the private investors who bought shares in 2015 to 2017 are still waiting for an exit. An EIS fund can't wait that long: University of Nottingham EIS Fund I sets its target over 10 years and expects returns in years 7 to 10. So it comes in later, mostly in second or later rounds of about £1m to £5m, years after a spin-out is formed. That shortens the wait but doesn't remove it: private company shares are illiquid, and exits can take longer than planned.
Promethean is not a holding of the fund, which is the university's first EIS fund and has no track record of its own. The fund will invest in University of Nottingham spin-outs selected by Nottingham Technology Ventures. The university reports that exits from its spin-outs have generated more than £18m for it since 2014, at an average multiple of more than 4x.
Please note: our office hours are weekdays, 9.30am - 5.30pm.
