Using copper to convert CO₂ to methane

'Tis a sad day when a phys.org article is this fluffy. Much better is the research article's Abstract:

> Carbon dioxide offers a unique opportunity as a feedstock for energy production through electrocatalysis. Methane production holds promise for its widespread applications and market demand. However, commercial viability faces challenges of low selectivity, current density, and high applied potential. Efforts to improve methane selectivity while suppressing multi-carbon products, e.g., ethylene, often involve lower alkalinity electrolytes. However, it reduces current density due to increased ohmic resistance without significant gains in the reaction yield. This study utilizes quantum mechanics computations to design a nano-cluster copper catalyst that redirects the reaction pathway from ethylene towards methane, even under alkaline conditions. We achieved a Faradaic efficiency (FE) of 85 %, a current density of 1.5 A/cm2, and stability of over 10 hours solely by controlling particle size in copper catalysts. This work paves the way to overcoming current limitations in electrocatalytic methane production and holds broader implications for advancing sustainable CO2 utilization in energy systems.

Also of interest - could this electrochemical setup be run in reverse, as a methane fuel cell? That I'm aware of, 85% efficiency would be far better than the current state of the art there.

Actual title: "Using copper to convert CO₂ to methane could be game changer in mitigating climate change".

Is there demand for methane? Why are there so many methane flares at oil wells in Texas, then?

At the rate solar, wind, and batteries are coming along, carbon capture is a waste of time and resources. Price alone is going to eliminate most demand for carbon based fuels. This is happening much faster than expected. See last week's Economist.

I’m not sure how effective using copper will be at scale, though I know you can use h2o and co2 to produce ch4 (methane) through a process called a Sabatier Reaction which involves the presence of a catalyst like nickel and high temperature. I’m guessing it would be a similar process here, except with copper?

Additionally, I recently discovered a company Valar Atomics who are working on small scale nuclear reactors to produce methane from h2o and co2 using this method.

- Valar Atomics announcement https://x.com/isaiah_p_taylor/status/1720418162985054350?s=4...

AFAICT there are 3 broad steps for creation of "green" methane.

- creating H2 from H2O - concentrating CO2 from either the atmosphere or the waste products of an industrial process such as cement production - creating CH4 from the H2 and the CO2. AKA Sabatier.

This paper uses H2 as an input, so is only talking about the last step. A cheaper/better Sabatier is nice, but AFAICT it's the least expensive step of the three.

FTA: “Our top finding was that extremely small copper nanoclusters are very effective at producing methane," continues Salehi. "This was a significant discovery, indicating that the size and structure of the copper nanoclusters play a crucial role in the reaction's outcome."”

How can that be surprising for “a new catalyst for converting carbon dioxide (CO2) into methane”? Are there any catalysts where their effectiveness doesn’t increase with surface area?

Also, if they make them tiny (“we used copper catalysts with different sizes, from small ones with only 19 atoms to larger ones with 1000 atoms”), how do you make sure you don’t pump out the catalyst with the methane? A filter?

I am having trouble understanding the details here.

How expensive is this process?

Is it feasible to scale this?

Are other catalysts better than this one at producing methane from CO2?

I had recently written a detailed article about e-methane, including how it compares to other hydrogen derivatives. tl;dr is that there are a lot of doubts whether e-methane makes any sense, as you usually end up either preferring hydrogen directly, or, if you need something with a carbon atom, you likely will use methanol.

Here's the article: https://industrydecarbonization.com/news/is-there-a-place-fo...

I had posted it on HN, but didn't get upvoted.

Water + CO2 into methane and oxygen. Hopefully just in time for the SpaceX Mars mission.

This is nonsense. There's not enough demand for methane and methane itself is an even worse greenhouse gas than CO2.

Doesn't pass basic thermodynamics.

If this finding is worth it, strap the machine doing it onto a car with methane motor (already exists) and you'll have an Perpetuum mobile.