High Efficiency Electrocatalytic Conversion of CO2 to CO

Managing CO₂ emissions is a major technical challenge associated with the use of fossil fuels. Catalytic conversion of CO₂ into valuable chemicals, such as methane, methanol, and CO, can be employed to help offset carbon capture costs while reducing greenhouse gas emissions. These chemicals may be used directly or subjected to further chemical processing.  NETL has developed a patented technology for high efficiency electrocatalytic conversion of CO₂ to CO.

The first invention is an apparatus and method to produce a nanocatalyst composed of ligand-protected Au25 clusters. The second invention describes a method for the control and isolation of differentially charged Au25 nanocatalyst clusters. This second method uses photoexcitation of the Au25 cluster in the presence of oxygen and a counter ion to specifically control the charge state of the catalyst. The method also describes the incorporation of nanocatalysts onto a support structure for charge-dependent reactivity. 

Both these technologies provide charge specific Au25 clusters that have been demonstrated to convert CO₂ to CO with 99 plus percent electron (Faradaic) efficiency and at catalytic rates that are approximately 10 to 100 times greater than other state-of-the-art electrocatalytic technologies. Charge-state dependent reactivity has also been shown to enhance the reduction of O₂ and the oxidation of CO. 

Overall, these technologies provide a way of creating catalysts with precisely controlled charges and tunable catalytic activity. Improved catalytic rates, electron (Faradaic) efficiencies, and product selectivities directly address core technical issues that have prevented the development of effective and scalable electrocatalytic technologies for CO₂ utilization.