![Scientists from Brown University have developed a technique that converts carbon dioxide (CO2) to carbon monoxide (CO) using gold nanoparticles. The CO can then be […]](/wp-content/uploads/2013/02/NEWSICON2-620x300.png "Gold nanoparticles hold promise for Carbon Dioxide recycling")
Scientists from Brown University have developed a technique that converts carbon dioxide (CO2) to carbon monoxide (CO) using gold nanoparticles. The CO can then be used to make alternate fuels and other useful chemicals. The study, published in the Journal of the American Chemical Society could be the first step in finding a way to recycle CO2 at a commercial scale.
Gold foil can be used as a catalyst in the conversion from CO2 to CO. The problem is that it tends to lead to the production of hydrogen as a byproduct and isn’t very efficient. The team at Brown tested out nanoparticles of different sizes and found an odd pattern emerged: the 8 nanometre particles worked very well at converting CO2 – with a 90% conversion rate. Larger and smaller sizes – such as 4,6 and 10 nm were not as successful. “At first, that result was confusing,” said Andrew Peterson, one of the senior contributors to the study. “As we made the particles smaller we got more activity, but when we went smaller than eight nanometres, we got less activity.”
This difference is due to particles changing shape at different sizes. As nanoparticles get smaller their shapes become more irregular – creating more edges, corners and flat regions. The size that had the highest number of edge sites – the locations where CO2 to CO conversion is catalysed – in relation to the number of corners (where hydrogen by-product is produced) was at 8nm.
Given the impact of carbon dioxide -amongst other greenhouse gases- on climate change, a way of recycling CO2 into something useful is of great interest to scientists and the public alike. The authors of the study have expressed their confidence that this process could be scaled up to be used commercially, “Because we’re using nanoparticles, we’re using a lot less gold than in a bulk metal catalyst,” said Shouheng Sun, one of the lead authors of the paper. “That lowers the cost for making such a catalyst and gives the potential to scale up.”
