Author Topic: "Cheap catalyst takes sunlight and carbon dioxide, makes methane"  (Read 925 times)

Offline Proponent

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John Timmer has an interesting article on Ars Technica.  Though the headline is about methane production, it appears to be easier to make carbon monoxide, which might be the way to go on, e.g., Mars.

Here's the link to the underlying paper in Nature.

EDIT:  Fixed first link, per following post.  Thanks to Crispy.
« Last Edit: 07/29/2017 12:23 PM by Proponent »

Offline Crispy

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Offline stefan r

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John Timmer has an interesting article on Ars Technica.  Though the headline is about methane production, it appears to be easier to make carbon monoxide, which might be the way to go on, e.g., Mars.

Here's the link to the underlying paper in Nature.

Higher efficiency would be important.  There is less sunlight on Mars and we have to ship all the way from earth.  In the article it says:
Quote
One thing that's clear is that this is an utterly abysmal way of using light energy, with a quantum yield of about 0.18 percent, meaning that only a tiny fraction of the photons supplied are used as energy to produce methane. By contrast, a lot of catalysts that split water using light produce hydrogen with a quantum efficiency over five percent.

Offline john smith 19

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Correct link: https://arstechnica.co.uk/science/2017/07/cheap-catalyst-takes-sunlight-and-carbon-dioxide-makes-methane/
Clearly this is a starting point, not a system that's ready to deploy.  :(

But

Getting CO2 to react is so damm tough that doing it at room temp and pressure almost seems like magic to me. 

Yes Methane would be useful for a fuel on Mars but CO would be very valuable in its own right. CO is what coke is converted too in a blast furnace to reduce Iron.  With no known supplies of coal or oil on Mars you have to find another way to reduce that Iron oxide to Iron if you want to make stuff out of it.

[EDIT yet catalysts are capable of splitting water to H2 up to 5% efficiency but being able to do it with CO2 gives you the whole atmosphere, not just anywhere near a water supply. That's important if you're looking at real large scale settlement, not just a "flags and footprints" mission  :( ]

True 0.18% is "Abysmal" but what a vast opportunity for improvement.  8) An obvious move would be to replace the "sacrificial" electron donor with an actual electrode to allow continuous electron injection.

This molecule is so complex there should be lots of ways to vary it. This is one of those occasions when chemical robots, producing thousands of slightly different samples for testing should be able to brute-force something (ideally several somethings) better.

And that's before the ability to turn CO2 into Methane at will would radically change the debate on the issues of human generated climate change. But that's completely OT for this thread.
« Last Edit: 08/07/2017 07:38 AM by john smith 19 »
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