July 29, 2023
Affordable, Green Hydrogen — It Is Here, Near, or Nowhere in Sight (Again)?

News arrives from Israel’s Technion Institute that they have developed a stable catalyst that can split water at extravagantly low energy-levels – and haven’t ruled out being able to split water with energy levels obtainable from the sun.

In fact, the hope of rapid transformation in the field is one of the reasons that AkzoNobel Specialty Chemicals and Gasunie New Energy have partnered in a project aiming at “large scale conversion of sustainable electricity into green hydrogen via the electrolysis of water.”

Intended for Delfzijl in the Netherlands, the installation would use a 20MW water electrolysis unit, the largest in Europe, to convert sustainably produced electricity into 3,000 tons of green hydrogen a year – enough to fuel 300 hydrogen buses. A final decision on the project is expected in 2019.

Why — and why now — is green hydrogen such a big, big deal?
Two reasons, really.

One, you’d solve the energy-storage problem of solar power, in a snap — you’d just split water to make hydrogen. (Don’t worry, when you use the hydrogen to, for example, power a car, the water re-forms out of the tailpipe. This isn’t a Water vs Fuel situation.)

Two, you’d have an affordable, biobased (hydrogen fuel) fuel you could make anywhere, in quantities exceeding the petroleum industry.

Scientists have not been able to crack the problem, in part because the catalyst that Nature evolved is complex, and has been described as the “the strongest biological oxidizing agent yet discovered”.

It comes down to controlling manganese, which is abundant and cheap, but the manganese catalysts yet developed never last and consume way too much energy.

Consequently, though Toyota has been working very hard on hydrogen vehicles, hydrogen as currently obtained via natural gas reforming is not green, nor competitively affordable. So, there might be a hundred hydrogen refueling stations in the US, about half of them in California.

In an article published in Nature Catalysis, Assistant Professor Galia Maayan of the Technion-Israel Institute of Technology presents a molecular complex (also called an artificial molecular cluster) that dramatically improves the efficiency of water oxidation. It does so by biomimicry – a field of engineering inspired by nature (bio=life, mimetics=imitation). In this specific case, the inspiration comes from the process of photosynthesis in nature.

The molecular complex developed by Maayan is expected to change this situation. This cluster, which is actually a complex molecule called Mn12DH, has unique characteristics that are advantageous when splitting water.

Experiments conducted with this complex demonstrate that it produces a large quantity of electrons (electric current) and a significant amount of oxygen and hydrogen, despite a relatively low energetic investment. No less important, it is stable – meaning that it is not easily demolished, like other Mn-based catalysts.

 

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