A fuel cell is almost like a battery that has replenishable fuel. Instead of charging a battery with an electric current, you recharge a fuel cell with something like hydrogen or you simply consume it from a tank much as an internal combustion engine consumes gasoline. However, fuel cells usually use a catalyst — it isn’t consumed in the reaction, but it is necessary and many fuel cells use platinum as a catalyst which is expensive. But what if you could use less catalyst and get a better result? That’s what researchers in Canada and the US are claiming in a recent paper. The key isn’t how much catalyst they are using, but rather the shape of the catalyst.
Of course, everyone wants to use less of the expensive catalyst but polymer electrolyte fuel cells have had a particular problem where reducing the amount of catalyst used causes a disproportionate drop in cell performance. This new approach uses spherical catalyst support that improves the distribution and utilization of the catalyst.
Stored hydrogen is often touted as the ultimate green energy solution, provided the hydrogen is produced from genuinely green power sources. But there are technical problems to be overcome before your average house will be heated with pumped or tank-stored hydrogen. One problem is that the locations that have lots of scope for renewable energy, don’t always have access to plenty of pure water, and for electrolysis you do need both. A team from Melbourne University have come up with a interesting way to produce hydrogen by electrolysis directly from the air.
Redder areas have more water risk and renewable potential
By utilising a novel electrolysis cell with a hygroscopic electrolyte, the so-called direct air electrolysis (DAE) can operate with humidity as low as 4% relative, so perfectly fine even in the most arid areas, after all there may not be clouds but the air still holds a bit of water. This is particularly relevant to regions of the world, such as deserts, where there is simultaneously a high degree of water risk, and plenty of solar potential. Direct electrolysis of saline extracted at coastal areas is one option, but dealing with the liberated chlorine is a big problem.
The new prototype is very simple in construction, with a sponge of melamine or a sintered glass foam soaked in a compatible electrolyte. Potassium Hydroxide (alkaline) was tried as was Potassium Acetate (base) and Sulphuric Acid, but the latter degraded the host material in a short time. Who would have imagined? Anyway, with electrolysis cell design, a key problem is ensuring the separate gasses stay separate, and in this case, are also separate from the air. This was neatly ensured by arranging the electrolyte sponge fully covered both electrodes, so as the hygroscopic material extracted water from the air, the micro-channels in the structure filled up with liquid, with it touching both ends of the cell, forming the circuit and allowing the electrolysis to proceed.
Hydrogen, being very light, would rise upward through holes in the cathode, to be collected and stored. Oxygen simply passed back into the air, after passing though the liquid reservoir at the base. Super simple, and from reading the paper, quite effective too.
You can kind of imagine a future built around this now, where you’re driving your hydrogen fuel cell powered dune buggy around the Sahara one weekend, and you stop at a solar-powered hydrogen fuel station for a top up and a pasty. Ok, possibly not that last bit.
Hydrogen fuel is promising, and while there’s plenty of hydrogen in the air and water, the problem is extracting it. Researchers have developed a way to use aluminum nanoparticles to rip hydrogen out of water with no additional energy input. It does, however, require gallium to enable the reaction. The reaction isn’t unknown (see the video below), but the new research has some interesting twists.
Aluminum, of course, is cheap and plentiful. Gallium, not so much, but the process allows recovery and reuse of the gallium, so that makes it more cost-effective. There is a patent pending for the process and — of course — the real trick is making the aluminum nanoparticles. But if you have that, this is a simple way to extract hydrogen from water with no extra energy and at room temperature. Since the reaction of creating aluminum oxide and releasing hydrogen with gallium is pretty well-known, it appears the real research here is determining the optimal properties of the aluminum and the ratio of aluminum to gallium.
While gallium isn’t a common item around the typical hacker’s workshop — unless you count the stuff bound up in semiconductors — it isn’t that expensive and it is relatively easy to handle. Hydrogen, though, not so much — so if you do decide to use this method to produce hydrogen, be careful!
We’ve seen gallium robots and even an antenna. So if you do get some of the liquid metal, there are plenty of experiments to try.
Hydrogen has long been touted as the solution to cleaning up road transport. When used in fuel cells, the only emissions from its use are water, and it eliminates the slow recharging problem of battery-electric vehicles. It’s also been put forth as a replacement for everything from natural gas supplies to laptop batteries.
Toyota has been pushing hard for hydrogen technology, and has worked to develop vehicles and infrastructure to this end. The company’s latest efforts involve a toteable hydrogen cartridge – letting you take hydrogen power on the go!
Doing the rounds among motorcycle enthusiasts for the last week has been a slightly unusual machine variously portrayed as running on water or sea water. This sounds like the stuff of the so-called “Free energy” fringe and definitely not the normal Hackaday fare, but it comes alongside pictures of a smiling teenager and what looks enough like a real motorcycle to have something behind it. So what’s going on? The answer is that it’s the student project of an Argentinian teenager [Santiago Herrera], and while it’s stretching it a bit to say it runs on sea water he’s certainly made a conventional motorcycle run on the oxygen-hydrogen mix produced from the electrolysis of water. The TikTok videos are in Spanish, but even for non-speakers it should be pretty clear what’s going on.
It’s obvious that the bike is more of a student demonstrator than a road machine, as we’re not so sure a glass jar is the safest of receptacles. But the interesting part for us lies not in the electrolysis but in the engine. it appears to be a fairly standard looking motorcycle engine, a typical small horizontal single. It’s running on a stoichiometric mix of oxygen and hydrogen, something that packs plenty of punch over a similar mix using air rather than oxygen. It would be fascinating to know the effect of this mixture on an engine designed for regular gasoline, for example does it achieve complete combustion, does it burn hotter than normal fuel, and does it put more stress on the engine parts?
As we all know, the lightsaber is an elegant weapon, for a more civilized age. [Alex Burkan] is doing what he can to bring that technology to fruition, and even secured a Guinness World Record in the process.
Melty melty.
The build relies on an electrolyzer, splitting water into hydrogen and oxygen gas which is stored in a small tank. This gas can then be released and combusted in a burning stream, creating a weapon with a vague resemblance to a movie-spec lightsaber. With the hydrogen torch burning at temperatures of thousands of degrees, it’s hot enough to melt steel just like in the films.
While the concept of operation is simple, actually building such a device in a handheld size is incredibly difficult. [Alex] highlights key features such as the flashback arrestor that stops the gas tank exploding, and the output nozzle that was carefully designed to produce a surprisingly long and stable flame.
The resulting device only burns for 30 seconds, so you’ve only got a short period of time to do what you need to do. However, unlike previous designs we’ve seen, it doesn’t use any external gas bottles and is entirely self-contained, marking an important step forward in this technology. Video after the break.
Even if you never want to generate hydrogen, [Maciej Nowak’s] video (embedded below) is interesting to watch because of the clever way the electrode is formed from stainless steel washers. You’ll need heat shrink tubing, but you ought to have that hanging around anyway. Building the electrode using the techniques in the video results in a lot of surface area which is important for an electrochemical reaction.
A standard rechargeable cell provides power for the generator which resides in a modified plastic bottle. The overall build looks good even though it is all repurposed material.
sponge fully covered both electrodes, so as the hygroscopic material extracted water from the air, the micro-channels in the structure filled up with liquid, with it touching both ends of the cell, forming the circuit and allowing the electrolysis to proceed.
