> Fuel cell catalyst material has been cost prohibitive.

Maybe, maybe not. Lots of people have been working on low cost fuel cells:

https://www.greencarcongress.com/2011/04/pani-20110421.html

https://www.greencarcongress.com/2016/01/20160115-udel.html

https://www.greencarcongress.com/2019/12/20191216-suryanto.h...

Toyota thinks they can build fuel cell cars cheaper than battery electrics:

https://www.thedrive.com/tech/26050/exclusive-toyota-hydroge...

> Interesting research but I don’t understand the commercial value.

They are more uses for hydrogen than just fueling vehicles. For example, you can use hydrogen in steel production:

https://www.en-former.com/en/hydrogen-revolution-steel-produ...

> That came when in 2003 Hirose’s boss Mitsuhisa Kato told him that “it’s time to join the enemy” and switch from hybrid to working on hydrogen.

Hahahaha

Well, that's what the research is for, to determine if it can be done with cheaper materials? You don't have to consume it in a fuel cell, it can be burned directly, and it's an input to some industrial chemical processes. It can also be added to the existing natural gas system in small quantities without modification, like the use of ethanol in petrol.

(The real problem is that fracked gas is so cheap)

The general subject: https://en.wikipedia.org/wiki/Power-to-gas

> Extracting pure never seemed like a problem to me

But then it's just energy carrier. You must use other sources of energy to produce it.

The process described produces hydrogen directly from the sun.

Not sure where you’re getting this:

> directly from the sun

As that’s not what the article describes. FTA: “ efficiently producing 25 times more hydrogen fuel by using a specific type of rust and light source.

Scientists achieved this new technique by using light from a mercury/xenon lamp”

So no - it’s not “the sun”, and it undoubtedly requires more electricity to run the lamp than can be harvested from the hydrogen produced.

Well yeah, what are you going to do in the lab: run a light pipe up to the roof and split off a portion into a power meter to normalize results by season+time+weather, or run a constant power lamp to control illumination power?

Maybe with mirrors, you might be able to do something like boiling water and getting hydrogen, getting two energy sources from water?

With renewables, carrying the energy is the biggest problem we have. Producing enough is entirely feasiblr with current technology.

It is. But one "easy" way of transporting it is throwing it into the electrical grid.

I don't think we'll have hydrogen cars necessarily, but if you can produce H2 easily, you can generate electricity with it.

Liquified hydrogen is the best possible fuel for aircraft, newly practical since advances in aerogel production that make well-insulated tanks practical.

It will unfortunately need new airframes, because even liquified it needs a fair bit more room than diesel. But once those are going, nobody will be able to compete with them. The hydrogen can be produced right at the airport from solar electric at minimum spot prices.

With this development, some of it can be produced without the round trip through electrics.

> With renewables, carrying the energy is the biggest problem we have.

Storing energy is the biggest problem we have. (Hydrogen can help with that.)

The technical term for this is "water splitting" and there are about 20000 papers published on the topic per year. So at least the ones providing money to academia are convinced that it is a problem worth solving. FWIW, the professor I knew working in this field and also owning a startup in the field recently switched from a hydrogen powered car to battery power. However as others noted, hydrogen is great to be converted to liquid fuel, because you won't be flying transatlantic on battery power any time soon.

You can always make Methane from Hydrogen.

But cost effectively? Even with free H2, seems the CH4 is expensive to produce.