With record deforestation coupled with record carbon emissions, our atmosphere has been increasingly clogged with greenhouse gasses that contribute to global warming. Chemists have dreamed of putting some of that carbon to good use, potentially in the form of biofuel. You can't fill up your tank with it quite yet, but scientists have come one step closer in making this dream a reality. The research was led by Peidong Yang of the University of California Berkeley, and the paper was published in Nature Communication.
The key to this technique will be to replicate photosynthesis and reduce carbon dioxide into carboxylic acid and carbon monoxide. The amount of energy required for this reaction has been problematic in the past. A catalyst needs to bind with the carbon dioxide to spur the reaction, without actually reacting itself.
Experimenting with a variety of nanoparticle alloys, the team found that there was an important relationship between the electronic component, which affects the metal's ability to bind the CO2, and the geometric component, which manipulates the atomic arrangement.
“Acting synergistically, the electronic and geometric effects dictate the binding strength for reaction intermediates and consequently the catalytic selectivity and efficiency in the electrochemical reduction of carbon dioxide,” Yang said in a press release, “In the future, the design of carbon dioxide reduction catalysts with good activity and selectivity will require the careful balancing of these two effects as revealed in our study.”
Of all the alloys examined, a gold-copper bimetallic nanoparticle demonstrated the most desirable attributes for reducing carbon dioxide to potentially create biofuel. Though it isn't a perfect system, the technique can be refined in the future to perform at a higher level.
“The ordered monolayers served as a well-defined platform that enabled us to better understand their fundamental catalytic activity in carbon dioxide reduction,” Yang explained. “Based on our observations, the activity of the gold-copper bimetallic nanoparticles can be explained in terms of the electronic effect, in which the binding of intermediates can be tuned using different surface compositions, and the geometric effect, in which the local atomic arrangement at the active site allows the catalyst to deviate from the scaling relation.”
In addition to reducing carbon dioxide, the researchers believe that this catalyst could have other implications as well for other reactions.
“We expect the effects we observed to be universal for a wide range of catalysts, as evidenced in other areas of catalysis such as the hydrogen evolution and oxygen reduction reactions,” added co-author Dohyung Kim. “The factors we have identified are based on the solid concept of electrocatalysis.”