Replacing Natural Photosynthesis
Directly or indirectly, a massive amount of the energy we use has been produced through photosynthesis. This is of course true of the calories powering our bodies, but ultimately also of fossil fuels, which are just “stored” photosynthesis from plants that died eons ago.
So, many efforts have been dedicated to either improving natural photosynthesis or leveraging it for new uses, like creating biofuels from algae. Building it at scale could prove crucial in limiting the rising CO2 concentration in the atmosphere.
But what if we could mimic the photosynthesis process without having to deal with living organisms? It is after all an electrochemical process which does not necessarily require living cells to happen. This is the promise of so-called “artificial photosynthesis”.
It would elevate our ability to capture the sun’s energy one step above photovoltaics, which can “only” create electricity out of sunlight but not directly affect chemical reactions.
Three researchers at the Japan Advanced Institute of Science and Technology (JAIST) and the University of Tokyo might have brought this technology one step closer to reality. In a paper published in Chemical Communications under the title “Bioinspired hydrogels: polymeric designs towards artificial photosynthesis”.
How Does Photosynthesis Work?
In plants, photosynthesis is, roughly speaking, the process of taking in CO2 and water, using light as an energy source, and producing carbohydrates and oxygen.
Source: Britannica
That said, it seems that this can be reduced to a very simple chemical equation and could be easily replicated artificially.
Source: Britannica
It is another story when you look at how it is done. Plant photosynthesis is actually one of the most complex biochemical machinery, with dozens of intermediary reactions, a myriad of sub-components, and sometimes not-so-well-understood molecular mechanisms involving elaborate electron movements.
The synthetic explanation of this topic in the Britannica encyclopedia is no less than 10,000 words. Scientists studying it have to deal with rather more complex schematics to start having an overview of photosynthesis:
Source: Lumen Learning
While mostly used in nature to create carbohydrates, photosynthesis could in theory be used for many other applications using light as an energy source, like for example the synthesis of hydrogen out of water (photocatalysis).
Bioinspired Hydrogels For Hydrogen Production
As one of the steps of natural photosynthesis is the splitting of water into oxygen and 2H+ atoms, it seems that replicating only that step would be easier than trying to mimic the entire process. This is what the Japanese researchers have worked on, using hydrogels.
Source: Chemical Communications
They used functional molecules, such as ruthenium complexes and platinum nanoparticles, which work together to simulate the natural process of photosynthesis and are known as powerful photocatalysts. The innovation is in how they organized these particles:
“What’s unique here is how the molecules are organized within the hydrogel. By creating a structured environment, we’ve made the energy conversion process much more efficient.”
Reina Hagiwara – PhD. student at JAIST
Source: Chemical Communications
Improved Efficiency
Another key improvement of using hydrogel compared to previous methods is that it keeps the metallic particles from clumping together, which tends to reduce the efficacy of the process.
“The biggest challenge was figuring out how to arrange these molecules so they could transfer electrons smoothly. By using a polymer network, we were able to prevent them from clumping together, which is a common issue in synthetic photosynthesis systems.”
Kosuke Okeyoshi – Associate professor at JAIST
The end result was a much more efficient photocatalysis, producing more hydrogen than older techniques.
Source: Chemical Communications
Light Catching Gel
Another factor in improved efficiency is that the gel essentially locks in the light, increasing its chance of powering the desired chemical reaction.
The careful crafting of the microgel was optimized to create diameters smaller than the wavelength of visible light. This also allowed to integrate the platinum and ruthenium microscopic particles in the gel into an organized mesh.
Source: Chemical Communications
The Key To The Hydrogen Revolution?
Hydrogen, or ammonia made from hydrogen, has long been considered a potential ideal fuel to power the world with green energy.
By being in a chemical form instead of electrical, hydrogen could store green energy over a much longer period and be a better replacement for fossil fuel than batteries in key applications like shipping or heavy industries.
The problem is that the production of hydrogen through electrolysis is a very energy-consuming process and a fairly inefficient one as well. This results in most of the green energy used to produce hydrogen being wasted, damaging the economics of the idea.
This efficiency problem of green hydrogen is fundamentally that the current concept requires too many steps: light -> DC current -> electrolysis -> hydrogen generation. Each extra step reduces efficiency and costs extra capital & resources for the machinery involved.
This gets even worse if the DC current needs to be turned into AC and carried away by the grid from solar farms to the hydrogen synthesis site.
Direct photocatalysis would turn it into “light -> hydrogen generation” without any intermediary steps.
The Next Steps
Better Polymers
This publication demonstrates that a carefully organized network of photocatalytic particles can be a game changer in hydrogen production. The hydrogel used here might be just a stepping stone.
The researchers expect that more advanced polymer networks will be designed. This could include fixing the catalytical components not only as small particles but as long, thin molecular chains, increasing the contact surface and light-catching. The future use of natural supramolecules, such as tubulin/microtubules, is also possible.
More Than Hydrogen
The study focused on hydrogen generation, but this is by far not the only chemical reaction that could be catalyzed by sunlight.
For example, Japanese researchers at Osaka have found a way to generate fumaric acid from bicarbonate and biomass-derived pyruvic acid, by using another form of artificial photosynthesis.
Beyond Platinum
Many of the hydrogen generation methods rely on splitting water molecules using platinum or other rare metals of the same family as ruthenium. And this could be one of the arguments for investing in platinum, besides hybrid vehicles’ growing popularity.
At the same time, the high cost of platinum has encouraged researchers to find alternatives that are more cost-efficient.
You can read some examples in Hydrogen Production Advancements with Nickel Based Electrolysis” and “Generating Hydrogen by Splitting Water with Embedded Swarf”.
Maybe these advancements in alternatives to platinum could be combined with the hydrogel and photocatalysis discussed above, to create a very low-cost hydrogen production method using only cheap metal, polymers, and sunlight.
Investing In Artificial Photosynthesis & Hydrogen
Artificial photosynthesis is for now very much a developing experimental field. However, the potential of the hydrogen economy is large enough to get many companies ready to invest in the possibility.
As many hydrogen production methods rely on platinum, this can be an option: It is actually possible to directly buy platinum for investment in physical metal form, with most precious metal bullion sellers offering coins and metal bars of platinum. Platinum jewelry is also a possibility.
Traded physical platinum stockpile can also be accessed through the abrdn Physical Platinum Shares ETF (PPLT) and the GraniteShares Platinum Trust (PLTM).
You can invest in hydrogen-related companies through many brokers, and you can find here, on securities.io, our recommendations for the best brokers in the USA, Canada, Australia, and the UK, as well as many other countries.
If you are not interested in picking specific hydrogen-related companies, you can also look into ETFs like the VanEck Rare Earth and Strategic Metals ETF (REMX) for the platinum angle, or hydrogen-focused ETFs like the Global X Hydrogen ETF (HGEN) or the VanEck Hydrogen Economy UCITS (HDRO) which will provide a more diversified exposure to capitalize on the potential of hydrogen as an energy source.
Hydrogen Company
Ballard Power Systems Inc. (BLDP +1.57%)
Ballard Power Systems Inc. (BLDP +1.57%)
Ballard is a fuel cell manufacturer, and a pioneer of the technology with its first fuel cell bus in 1993.
The company is focused on heavy-duty markets: buses, trucks, trains/trams, ships, mining/construction, and power. While buses have been the core of the business, the company expects that by 2025, trucks will be a major business segment. It also expects Europe to stay its main market (50-60%), followed by North America (25%).
Trucking fuel cells are expected to keep growing and represent a $7.5B market in 2030 (from a $195B TAM), almost as large as all the other hydrogen/fuel cell applications combined.
Source: Ballard
Because of the higher power required and the need for quick charging, heavy-duty vehicles have been a good pick for hydrogen and fuel cells over lighter vehicles like cars.
It also reduces the need for catenary wire for rail and fast recharging for long-distance hauling.
Source: Ballard
The company is not a stranger to ammonia either, with for example a recent contract with Amogy to provide it with fuel cells for its “ammonia-to-power platform which relies on unique ammonia cracking technology”.
While EVs have a reasonable chance to quickly take over the car markets, heavier vehicles are harder to decarbonize.
With its established leadership in the sector, Ballard would be a prime beneficiary of a policy push toward a hydrogen economy.
The focus on fuel cells also allows the company to benefit from any cost-cutting in hydrogen generation technology, no matter the method, with or without platinum, and with or without photocatalysis.