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Topic: Obtain H2 gas from H20  (Read 2430 times)

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Offline rohan1020

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Obtain H2 gas from H20
« on: March 16, 2011, 08:24:07 AM »
hello..

I wanted to know if there is any method to produce hydrogen from water just by heating the water, may be in the presence of any catalyst.

I'm aware of electrolysis but I want to prepare hydrogen just be supplying heat.

Thanks...

Offline Enthalpy

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Re: Obtain H2 gas from H20
« Reply #1 on: March 17, 2011, 01:41:01 PM »
- Heat (really serious hot) does decompose water partially BUT (1) how do you separate both gases prior to recombination (2) what kind of solids shall resist?

- There are certainly less direct processes that use technological temperatures. Like: produce CO from CO2, use CO in other reactions to get H2. True chemists can tell you more - I'm not one.

- Wiki's article telling hot zirconium decomposes water into H2 and O2 at Fukushima is just false.

- H2 is good for fuel cells (is that your target?) but hydrocarbons or alcohols are better for gasoline engines and are easier to produce by thermal means.

- If you want to produce fuels by concentrated Sunlight, it's definitely a good idea. Storable, easier to use by present engines.

- This task is hard because oil and gas are so dirt-cheap. They get expensive through taxes. Processes like yours will be accepted by governments only if they compete with the cost before taxes, which is very difficult.

Offline DevaDevil

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Re: Obtain H2 gas from H20
« Reply #2 on: March 24, 2011, 02:23:50 PM »
- Wiki's article telling hot zirconium decomposes water into H2 and O2 at Fukushima is just false.

I am unaware of the wiki article, but what I do know is that metallic zirconium will easily oxidise in water forming protons and zirconium oxide (not oxygen indeed), while the balancing reaction in clean water would be the formation of hydrogen out of those protons.

ZrO2 + 4 H+ + 4 e- <--> Zr + 2 H2O;    E0 = -1.43V

balanced by

H2 <--> 2 H+ + 2 e-;  E0 = dependent on metal "electrode", 0V on Pt, ~ 0.4 V on Zr (101)(Rus. J. Electrochem. V. 38, No. 7, 2002, pp. 714)


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