Chemistry of producing fuel

[timojin]

Titania , Molysulfide , water and sun, Any suggestion ?

Lead researcher Dr Torben Daeneke, from RMIT University in Melbourne, Australia, said: "We found that mixing the compound with titanium oxide particles leads to a sunlight-absorbing paint that produces hydrogen fuel from solar energy and moist air.

"Titanium oxide is the white pigment that is already commonly used in wall paint, meaning that the simple addition of the new material can convert a brick wall into energy harvesting and fuel production real estate.

"Our new development has a big range of advantages," he said. "There's no need for clean or filtered water to feed the system. Any place that has water vapour in the air, even remote areas far from water, can produce fuel."

http://www.theage.com.au/technology...less-energy-from-water-vapour-20170612-gwpnoq

 

[DaveC426913]

One wonders what happens to all the oxygen liberated from the water.

Now you've got a wall offgassing fuel and its own oxidant. H and O are almost spontaneous in their desire to combust.

... don't light a match near that building...

 

[exchemist]

One wonders what happens to all the oxygen liberated from the water.

Now you've got a wall offgassing fuel and its own oxidant. H and O are almost spontaneous in their desire to combust.

... don't light a match near that building...

Yes, I am not all that impressed by this. OK so they have a catalyst for photolysis of water. Great. But there's a hell of lot more needed to make this useful than just painting it on a wall. They've done about 20% of the work. They speak airily about "membranes" to collect the hydrogen, but give no clue as to how this can work. If you have a "membrane" that collects the hydrogen, how do you separate the oxygen, and how do you still allow the surface to be in contact with moisture from the air?

 

[timojin]

Yes, I am not all that impressed by this. OK so they have a catalyst for photolysis of water. Great. But there's a hell of lot more needed to make this useful than just painting it on a wall. They've done about 20% of the work. They speak airily about "membranes" to collect the hydrogen, but give no clue as to how this can work. If you have a "membrane" that collects the hydrogen, how do you separate the oxygen, and how do you still allow the surface to be in contact with moisture from the air?

If we take this catalysts and separate them in two parts , 1) titania splits water with presence of UV light
2 ) Moly disulfide is a catalyst for hydrogenation . Moly disulphide is oxidised in presence of oxygen to
to molybdenum sulphate

 

[Q-reeus]

From the article linked to in #1:

The RMIT research team has released the findings to the public domain, rather than patent it, so the design can be improved upon by the scientific community and fast-tracked for commercial use.

Dr Kalantar-zadeh said he hoped to see solar paint on city buildings and in the suburbs within years.

"People need such technology," he said. "We can sit on it for years and years and go through commercialisation by ourselves, but like this I hope we are doing a favour to the community."

Tertiary institutions in general are squeezed for funding and supposedly joint academic-industry partnerships are encouraged as a way to ease that, while simultaneously promoting healthy competition and innovation. In this bizarre case, either a sign of little real confidence in it's practicality, or a fool decision that RMIT board members who approved such generosity should pay dearly for - i.e sacked en masse.

 

[DaveC426913]

If we take this catalysts and separate them in two parts , 1) titania splits water with presence of UV light
2 ) Moly disulfide is a catalyst for hydrogenation . Moly disulphide is oxidised in presence of oxygen to
to molybdenum sulphate

OK, so we've painted a wall with this stuff.
It needs sunlight to work, so we can't cover it with gas-harvesting equipment.
It off-gasses hydrogen as it oxidizes.

If it's oxidizing then it's not catalyzing. Catalyzing means the original material is left unaffected and can keep processing. That's antithetical to oxidation. So which is it?

 

[exchemist]

OK, so we've painted a wall with this stuff.
It needs sunlight to work, so we can't cover it with gas-harvesting equipment.
It off-gasses hydrogen as it oxidizes.

If it's oxidizing then it's not catalyzing. Catalyzing means the original material is left unaffected and can keep processing. That's antithetical to oxidation. So which is it?

There is a rather glib-looking arrow in the diagram that comes with the article, labelled " regeneration". However there is no explanation of how this occurs, though it looks as if it may take place at night, i.e. when there is no photolysis.

But it is all a bit unsatisfactory and premature-looking. The fact they have published it, instead of seeking a patent, suggests to me that maybe they themselves have no idea whether this can really be turned into a working system of hydrogen and oxygen production.

 

[timojin]

OK, so we've painted a wall with this stuff.
It needs sunlight to work, so we can't cover it with gas-harvesting equipment.
It off-gasses hydrogen as it oxidizes.

If it's oxidizing then it's not catalyzing. Catalyzing means the original material is left unaffected and can keep processing. That's antithetical to oxidation. So which is it?

I had problem from the beginning to understand .
I thought , Titania will split the water and Moly disulphide will pick up the oxygen to be converted to Mo O and SO2 , but there the color will change and the absorbent get depleted, I agree with you than this is not a catalyst , so Titania is the catalyst . Next you will have get the hydrogen through a platinum membrane .
In essence more information is needed.

 

[danshawen]

Any hydrogen absorbing metal should make this an easy system to make into a fuel cell. The hydrogen dissociates and gets collected into a metal mesh somewhere above the painted area. Easy, right?