Copper-gold nanoparticles convert CO2, may reduce greenhouse gas emissions

April 12, 2012

An electron microscopy image of hybrid gold/copper nanoparticles (credit: Zhichuan Xu)

MIT researchers have come up with a way to reduce the energy needed for copper to convert carbon dioxide: nanoparticles of copper mixed with gold.

They coated electrodes with the hybrid nanoparticles and found that much less energy was needed for these engineered nanoparticles to react with carbon dioxide (converting it to methane or methanol), compared to nanoparticles of pure copper.

Kimberly Hamad-Schifferli of MIT’s Hamad-Schifferli Group says the findings point to a potentially energy-efficient means of reducing carbon dioxide emissions from powerplants.

A paper detailing the results will appear in the journal Chemical Communications.


Copper — one of the few metals that can turn carbon dioxide into hydrocarbon fuels with relatively little energy — when formed an electrode and stimulated with voltage — acts as a strong catalyst, setting off an electrochemical reaction with carbon dioxide that reduces it to methane or methanol.

Various researchers around the world have studied copper’s potential as an energy-efficient means of recycling carbon dioxide emissions in powerplants. Instead of being released into the atmosphere, carbon dioxide would be circulated through a copper catalyst and turned into methane, which could then power the rest of the plant.

Such a self-energizing system could vastly reduce greenhouse gas emissions from coal-fired and natural-gas-powered plants.

But copper is temperamental: easily oxidized, as when an old penny turns green. As a result, the metal is unstable, which can significantly slow its reaction with carbon dioxide and produce unwanted byproducts such as carbon monoxide and formic acid.