Copper-Gold Nanoparticles Efficiently Convert Carbon Dioxide

The gold nanoparticles (in light red) and copper nanoparticles (in light green) form hybrid nanoparticles (dark red), which were turned into powder (foreground) to catalyze carbon dioxide reduction.

Copper is one of the few metals that can turn carbon dioxide into hydrocarbon fuels with relatively little energy, but it is temperamental and easily oxidized. MIT researchers have engineered nanoparticles of copper mixed with gold - which is resistant to corrosion and oxidation - making the copper much more stable. They coated electrodes with the hybrid nanoparticles and found that much less energy was needed for conversion.

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

To make the nanoparticles, Hamad-Schifferli and her colleagues mixed salts containing gold into a solution of copper salts. They heated the solution, creating nanoparticles that fused copper with gold. Xu then put the nanoparticles through a series of reactions, turning the solution into a powder that was used to coat a small electrode.

Going forward, Hamad-Schifferli says she hopes to look more closely at the structure of the gold-copper nanoparticles to find an optimal configuration for converting carbon dioxide. So far, the team has demonstrated the effectiveness of nanoparticles composed of one-third gold and two-thirds copper, as well as two-thirds gold and one-third copper.

(MIT)