First, yes this is cool new science. No one imagined nickel would work as a water-splitting electrocatalyst. This is very surprising, and awesome.
Second, the point of water-splitting is obviously not power generation. It's power storage, just like a battery, but with better transport and storage characteristics.
So what makes a hydrogen exposed freezing tank better suited for transport and storage than a chemical battery?
And to answer your question, much better energy density by mass.
Some little PDFs about the hurdles of hydrogen from one of my favorite tech writers:
http://www.tinaja.com/glib/resbn88.pdf
http://www.tinaja.com/glib/energfun.pdf
A hydrogen economy might be possible one day, but not until we find a natural H2 source that is as "free" as crude oil. Man made hydrogen will not work on a large scale. Electrolysis is one of the worst ways to make hydrogen, though it does have the highest "gee-whiz!" factor.
If we did have unlimited hydrogen spewing out of the ground people would seriously consider first cracking the H2 into hydrocarbons to make it easier to transport.
(Granted you'd also need to make coal out of co2, which is so much harder. but every little bit helps)
Not true. It has been known since the 1950s (and likely earlier) that Ni oxides can function as water splitting catalysts (both for hydrogen evolution and oxygen evolution half reactions).
But I agree with you, efficient-cheap catalyst is needed indeed. I'd like to know the efficiency of the system though...
A cylinder full of compressed hydrogen weighs less than a trunk full of AAA batteries, which cuts into economy.
The clunky bank of AAA batteries can be stationary in some water-splitting plant, whereas the hydrogen is light and portable.
Although touted as zero-emissions vehicles, most of the cars will run on hydrogen made from natural gas, a fossil fuel that contributes to global warming. Now scientists at Stanford University have developed a low-cost, emissions-free device that uses an ordinary AAA battery to produce hydrogen by water electrolysis.
You don't agree the juxtaposition gives the impression that the latter alternative won't contribute to global warming?
Edit: just to be clear, I'm not saying the research isn't useful. My issue is with the article.
Please don't be personally rude on Hacker News. This comment would be fine without the first two sentences.
I wish there were a way for users to suggest edits to each other's comments. My bet is that most of us have no idea when our comments include superfluous stuff that could easily be edited out. Suppose there were an easy way to send pull requests on comments. One could look at the diff and, if it improved the signal/noise ratio, simply accept the changes.
HN needs more sober second thought.
We're still interested in whatever might be done to curtail such downhill slides.