Gold nanoparticles are at the heart of a new process conceived and developed by researchers at the U.S. Department of Energy’s National Energy Technology Laboratory (NETL) that can efficiently convert carbon dioxide (CO2) into usable chemicals and fuels—a breakthrough that could lead to an effective industrial scale way to reduce CO2 emissions for a positive impact on the world’s environment. The innovation was recently detailed by NETL in the American Chemical Society (ACS) publication ACS Applied Materials & Interfaces.  

An effective CO2 conversion process must change CO2 from a waste product into a useful feedstock in an environmentally sustainable way, allowing the manufacture of renewable fuels and chemicals at costs comparable to more traditional processes. The problem is that most fossil fuel-powered CO2 conversion processes are currently “carbon positive” and do not help mitigate CO2 emissions. The process developed by NETL is a “carbon neutral” energy cycle, using renewable energy sources to recycle waste CO2 into chemicals and fuels without generating new CO2 emissions. The process will help slow global climate change by limiting CO2 emitted to the atmosphere, offer an environmentally friendly supplement to traditional energy sources, and enable sustainable use of our current fossil fuel resources.

Researchers developed a special form of gold nanoparticle that contains exactly 25 gold atoms to convert CO2. This “Au25” catalyst proved to be highly efficient; researchers were able to power a small CO2 reactor with inexpensive renewable energy sources, such as solar panels and solar-rechargeable batteries obtained from retail hobby shops.

Data obtained from the study also informs critical performance estimates needed to move the carbon-neutral energy cycle out of the lab and into industrially relevant applications. Based on their results, the research team estimates that state-of-the-art renewable energy sources like solar-cells and wind turbines are sufficient to convert metric tonnes of CO2 per day.

The peer-reviewed paper, titled “Efficient Electrochemical CO2 Conversion Powered by Renewable Energy,” was recently published in the ACS Applied Materials and Interfaces journal (volume 7, issue 28, pp. 15626-15632). The work was also recently featured as a nanotechnology spotlight in the online technology news outlet Nanowerk.