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I'm amazed at the ignorance in these comments. First, yes this is cool new science. No one imagined nickel would work as a water-splitting electrocatalyst. Thi

by nardi 12y ago

I'm amazed at the ignorance in these comments. 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.

alex_duf 12y ago
right, but using a AAA battery which is already storing energy doesn't serve any purpose. But I agree with you, efficient-cheap catalyst is needed indeed. I'd like to know the efficiency of the system though...
- petersellers 12y ago
  Using a AAA battery demonstrates that the process can be done using low voltage.
  - alex_duf 12y ago
    ooh, alright, now it makes sense to me. Thanks.
- kazinator 12y ago
  Even if we imagine ourselves in a crazy world in which banks of actual AAA batteries are used for water splitting (not only to demonstrate the low voltage) there can still be an advantage. 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.
mikexstudios 12y ago
"No one imagined nickel would work as a water-splitting electrocatalyst." 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).
- nardi 12y ago
  Of course you're right. I meant that no one thought nickel oxides would be practical compared to noble metal catalysts. I haven't read the article, but I assume they're using some kind of novel nanostructuring to increase the catalytic activity.
crististm 12y ago
I don't know about ignorance, but basically, the energy you get from splitting the water molecule (in the form of H2 and O2) is lower than the energy consumed to make the split. For storage you will also have to deeply freeze the gases unless you want to have huge tanks for storage So what makes a hydrogen exposed freezing tank better suited for transport and storage than a chemical battery?
- nardi 12y ago
  This is just pessimism. Yes, there are other hurdles to overcome for hydrogen. But this is a major advance in one of the primary pieces necessary for a hydrogen economy. What makes you think advances in other areas are impossible? And to answer your question, much better energy density by mass.
  - keenerd 12y ago
    Who cares about mass except NASA? H2 is terrible by volume, a liter of gasoline has more hydrogen in it than a liter of liquid H2 and the gasoline is a lot more safe. 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/resbn88.pdf http://www.tinaja.com/glib/energfun.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.
    - waps 12y ago
      And if you blast coal with it ... Guess what comes out ? (Granted you'd also need to make coal out of co2, which is so much harder. but every little bit helps)
- cjensen 12y ago
  A car which runs on hydrogen can be refueled in a few minutes. Batteries need an hour of charge or a battery swap which costs labor.
lutorm 12y ago
Give me a break. Did you read the article? 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.
- dang 12y ago
  > Give me a break. Did you read the article? Please don't be personally rude on Hacker News. This comment would be fine without the first two sentences.
  - jack-r-abbit 12y ago
    No disrespect... but nardi did, in fact, NOT read the article: https://news.ycombinator.com/item?id=8213612 https://news.ycombinator.com/item?id=8213612
    - nardi 12y ago
      I meant I hadn't read the paper. I had of course read the linked article, which is light on details of how they created the catalyst.
      - jack-r-abbit 12y ago
        My bad. When you said article, I thought you meant the linked article. I don't see any reference to a paper so clearly I have no idea what you are talking about. I'll just go about my day. :)
  - lutorm 12y ago
    Guilty, though I responded to the OPs "I'm amazed at the ignorance in these comments". You don't think that warrants the same comment?

by nardi 12y ago

alex_duf 12y ago

right, but using a AAA battery which is already storing energy doesn't serve any purpose. But I agree with you, efficient-cheap catalyst is needed indeed. I'd like to know the efficiency of the system though...

petersellers 12y ago
Using a AAA battery demonstrates that the process can be done using low voltage.
- alex_duf 12y ago
  ooh, alright, now it makes sense to me. Thanks.
kazinator 12y ago
Even if we imagine ourselves in a crazy world in which banks of actual AAA batteries are used for water splitting (not only to demonstrate the low voltage) there can still be an advantage. 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.

mikexstudios 12y ago

"No one imagined nickel would work as a water-splitting electrocatalyst." 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).

nardi 12y ago
Of course you're right. I meant that no one thought nickel oxides would be practical compared to noble metal catalysts. I haven't read the article, but I assume they're using some kind of novel nanostructuring to increase the catalytic activity.

crististm 12y ago

I don't know about ignorance, but basically, the energy you get from splitting the water molecule (in the form of H2 and O2) is lower than the energy consumed to make the split. For storage you will also have to deeply freeze the gases unless you want to have huge tanks for storage So what makes a hydrogen exposed freezing tank better suited for transport and storage than a chemical battery?

nardi 12y ago
This is just pessimism. Yes, there are other hurdles to overcome for hydrogen. But this is a major advance in one of the primary pieces necessary for a hydrogen economy. What makes you think advances in other areas are impossible? And to answer your question, much better energy density by mass.
- keenerd 12y ago
  Who cares about mass except NASA? H2 is terrible by volume, a liter of gasoline has more hydrogen in it than a liter of liquid H2 and the gasoline is a lot more safe. 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/resbn88.pdf http://www.tinaja.com/glib/energfun.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.
  - waps 12y ago
    And if you blast coal with it ... Guess what comes out ? (Granted you'd also need to make coal out of co2, which is so much harder. but every little bit helps)
cjensen 12y ago
A car which runs on hydrogen can be refueled in a few minutes. Batteries need an hour of charge or a battery swap which costs labor.

lutorm 12y ago

Give me a break. Did you read the article? 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.

dang 12y ago
> Give me a break. Did you read the article? Please don't be personally rude on Hacker News. This comment would be fine without the first two sentences.
- jack-r-abbit 12y ago
  No disrespect... but nardi did, in fact, NOT read the article: https://news.ycombinator.com/item?id=8213612 https://news.ycombinator.com/item?id=8213612
  - nardi 12y ago
    I meant I hadn't read the paper. I had of course read the linked article, which is light on details of how they created the catalyst.
    - jack-r-abbit 12y ago
      My bad. When you said article, I thought you meant the linked article. I don't see any reference to a paper so clearly I have no idea what you are talking about. I'll just go about my day. :)
- lutorm 12y ago
  Guilty, though I responded to the OPs "I'm amazed at the ignorance in these comments". You don't think that warrants the same comment?