Some background and context from someone tangentially related to the field:<p>1. The overall idea here is to take an intermittent energy source (e.g. solar power) and "store" it as chemical fuel, in this case hydrogen and oxygen. This is what plants do, and we can also view fossil fuels as resulting from the "storage" of millions of years of solar energy. Note also that you get the water back when you burn the hydrogen, so there is no net consumption of water, it's just a carrier.<p>2. While you can split water without a catalyst, most of the energy gets wasted as heat, so this is not a great way to go if you're trying to do energy storage.<p>3. Efficient catalysts exist for this reaction, but they are based on rare and expensive metals, typically Pd, Pt, and Ir. As a result, there has been a search for catalysts involving "first-row" metals such as Fe, Co, Ni, etc.<p>4. There are variety of metrics for an electrocatalyst (efficiency, stability, cost, etc), but it's a fair bet that if this were significantly better than state-of-the-art, it would be in Science or Nature rather than PNAS.
I emailed Jeannie and she sent me the paper. I'm an idiot about finding a place to post it or host it (or find it), but the title of the paper is:
"Highly active catalyst derived from a 3D foam of Fe(PO3)2/Ni2P for extremely efficient water oxidation"<p>Searched for that and got this: <a href="http://www.pnas.org/content/early/2017/05/10/1701562114.abstract" rel="nofollow">http://www.pnas.org/content/early/2017/05/10/1701562114.abst...</a>
I am really miffed at this quote:<p>"Hydrogen is the cleanest primary energy source we have on earth,” said Paul C. W. Chu, TLL Temple Chair of Science and founding director and chief scientist of the Texas Center for Superconductivity at UH.<p>This seems like sensationalism and poor science communication to me. Hydrogen isn't a primary energy source.
I am (was) a chemist but I find this research area somewhat puzzling. Electrolytic hydrogen production has been industrialized for more than a century. Put nickel electrodes in an aqueous solution of potassium hydroxide. Separate anode and cathode with a porous diaphragm. Run direct current through it. Get pure hydrogen. "Simple" alkaline electrolysis is only ~50% efficient, but that means there's only a factor of two efficiency gain possible no matter how good your catalyst. Large commercial electrolyzers from a decade ago reached ~70%. Why so much research on further marginal efficiency gains from new catalysts? Are there other costs that fall faster-than-linearly with improved efficiency?
WSU in 2016: <a href="https://news.wsu.edu/2016/10/25/better-water-splitting-catalyst/" rel="nofollow">https://news.wsu.edu/2016/10/25/better-water-splitting-catal...</a><p>Missouri U: <a href="http://onlinelibrary.wiley.com/doi/10.1002/cssc.201601631/abstract;jsessionid=0CBBE4F0EBB05A15864081DE3851C125.f02t02" rel="nofollow">http://onlinelibrary.wiley.com/doi/10.1002/cssc.201601631/ab...</a><p>Stanford: <a href="http://science.sciencemag.org/content/353/6303/1011.full" rel="nofollow">http://science.sciencemag.org/content/353/6303/1011.full</a><p>Lots and lots and lots of research going on in this space. So far nothing that can be used to produce hydrogen at scale.
> That would solve one of the primary hurdles remaining in using water to produce hydrogen, one of the most promising sources of clean energy.<p>What? No. Hydrogen is not a source of energy, it's a storage format. A more efficient catalyst will certainly help with losses when storing the energy, but there's no net gain.
Some total n00b questions:<p>Could this also be used in desalination? Turn into hydrogen, burn to convert back to water, feed it catalyst material like a fuel? (I'm not really sure how these catalysts work, do you like push water through them? and out comes gases?)
So, uh, do catalysts like this reduce the waste heat you get when electrolyzing water with a cruder setup? Because there's nothing but a specific minimum energy input that's going to break the bonds between hydrogen and oxygen.
>And unlike solar power, wind power and other “clean” energy, hydrogen can be easily stored<p>Sure it's easier than other forms, but it's my understanding that there are some significant challenges in storing hydrogen?
What are the key metrics for catalysts? Obviously cost is one. Round-trip energy efficiency? How does this measure up to existing commercial alternatives? How about against no-catalyst electrolysis?
Anyone know what some "bigger picture" uses of this would be? It seems significant, but I'm not a chemist. Energy sources, desalination, etc?
mods, the original title should be preserved, currently it is :
"U of Houston discovers catalyst that splits water into hydrogen and oxygen"<p>But the original title is : "UH Researchers Report New, <i>More Efficient</i> Catalyst for Water Splitting"<p>catalyst for water splitting aren't new. the article even says it :<p>>The catalyst, composed of ferrous metaphosphate grown on a conductive nickel foam platform, is far more efficient than previous catalysts, as well as less expensive to produce.
When I see anything related to splitting water into hydrogen, I'm worried that we're going to use water for energy on top of using to hydrate people.<p>Still today, over 10% of the world population don't have access to clean water. I'm also curious on how clean the water needs to be to be used with this catalyst. AFAIK, most catalyst conversion need pretty pure water, in which case, we would not only use water, but use _clean_ water, which is even more scare than "dirty" water...
How much water would this process need to make enough energy for this to have an impact? Presuming we wouldn't use up our fresh water resources for this and that it would come from the ocean, but would this process create potential threats to the marine habitat as the mineral/chemical concentrations of the ocean water shifted?