Remove ads

Introducing the LemonFools Personal Finance Calculators

Cheaper hydrogen?

Scientific discovery and discussion
Infrasonic
Lemon Quarter
Posts: 1074
Joined: November 4th, 2016, 2:25 pm
Has thanked: 105 times
Been thanked: 154 times

Cheaper hydrogen?

#58143

Postby Infrasonic » June 6th, 2017, 3:17 pm

https://phys.org/news/2017-06-ultrathin ... eaper.html

UNSW Sydney chemists have invented a new, cheap catalyst for splitting water with an electrical current to efficiently produce clean hydrogen fuel.
The technology is based on the creation of ultrathin slices of porous metal-organic complex materials coated onto a foam electrode, which the researchers have unexpectedly shown is highly conductive of electricity and active for splitting water.
"Splitting water usually requires two different catalysts, but our catalyst can drive both of the reactions required to separate water into its two constituents, oxygen and hydrogen," says study leader Associate Professor Chuan Zhao.
"Our fabrication method is simple and universal, so we can adapt it to produce ultrathin nanosheet arrays of a variety of these materials, called metal-organic frameworks.
"Compared to other water-splitting electro-catalysts reported to date, our catalyst is also among the most efficient," he says.

Cont.

tjh290633
Lemon Quarter
Posts: 2427
Joined: November 4th, 2016, 11:20 am
Has thanked: 150 times
Been thanked: 738 times

Re: Cheaper hydrogen?

#58261

Postby tjh290633 » June 6th, 2017, 11:11 pm

I wasn't aware that electrolysis of water required a catalyst.

Is he in fact referring to the electrode materials?

TJH

XFool
Lemon Quarter
Posts: 2464
Joined: November 8th, 2016, 7:21 pm
Been thanked: 145 times

Re: Cheaper hydrogen?

#62939

Postby XFool » June 26th, 2017, 1:05 pm

tjh290633 wrote:I wasn't aware that electrolysis of water required a catalyst.

It doesn't "require" it. But it very much helps!

tjh290633
Lemon Quarter
Posts: 2427
Joined: November 4th, 2016, 11:20 am
Has thanked: 150 times
Been thanked: 738 times

Re: Cheaper hydrogen?

#63026

Postby tjh290633 » June 26th, 2017, 5:00 pm

XFool wrote:
tjh290633 wrote:I wasn't aware that electrolysis of water required a catalyst.

It doesn't "require" it. But it very much helps!

Sounds to me that the porous electrode has much more surface area, so can release more gas. I still don't think that you can get more gas than the electrical current can release.

Some thermodynamic calculations might convince me.

TJH

XFool
Lemon Quarter
Posts: 2464
Joined: November 8th, 2016, 7:21 pm
Been thanked: 145 times

Re: Cheaper hydrogen?

#63044

Postby XFool » June 26th, 2017, 6:07 pm

tjh290633 wrote:
XFool wrote:
tjh290633 wrote:I wasn't aware that electrolysis of water required a catalyst.

It doesn't "require" it. But it very much helps!

Sounds to me that the porous electrode has much more surface area, so can release more gas. I still don't think that you can get more gas than the electrical current can release.

Like most things catalytic, I expect it is more a matter of rate of reaction than getting "more gas than the electrical current can release".

For instance, if you put a little H2SO4 into distilled water it will electrolyse MUCH faster than pure water ever would. But you still get just Hydrogen and Oxygen at the electrodes, AFAIK.

johnhemming
Lemon Quarter
Posts: 1371
Joined: November 8th, 2016, 7:13 pm
Has thanked: 3 times
Been thanked: 136 times

Re: Cheaper hydrogen?

#63058

Postby johnhemming » June 26th, 2017, 7:30 pm

There might be a question as to how much heat is generated as well as free hydrogen (and oxygen).

https://en.wikipedia.org/wiki/Electrolysis_of_water
Reported working efficiencies were for alkaline in 1996 lying in the 50–60% range for the smaller electrolysers and around 65–70% for the larger plants.[22] Theorical efficiency for PEM electrolysers are predicted up to 94%.[23] Ranges in 2014 were 43–67% for the alkaline and 40–67% for the PEM, they should progress in 2030 to 53–70% for the alkaline and 62–74% for the PEM.[20]

tjh290633
Lemon Quarter
Posts: 2427
Joined: November 4th, 2016, 11:20 am
Has thanked: 150 times
Been thanked: 738 times

Re: Cheaper hydrogen?

#63266

Postby tjh290633 » June 27th, 2017, 6:29 pm

XFool wrote:Like most things catalytic, I expect it is more a matter of rate of reaction than getting "more gas than the electrical current can release".

For instance, if you put a little H2SO4 into distilled water it will electrolyse MUCH faster than pure water ever would. But you still get just Hydrogen and Oxygen at the electrodes, AFAIK.


That, I think, is down to mobility of charged species and the conductivity of a solution, compared with pure water. Somewhere I have a large book called "Physical Chemistry", which might have the answer, which I doubt has changed over the intervening 60 years.

TJH


Return to “Science”

Who is online

Users browsing this forum: No registered users and 1 guest