The discovery of a new electrocatalyst brings carbon dioxide one step closer to serving as a sustainable energy Brookhaven scientists pictured at the beamline 8-ID, where they used ultra-bright x-ray light to "see" the chemical complexity of a new catalytic material. Source: U.S. Brookhaven National Laboratory precursor. Nickel single atoms dispersed into graphene sheets, without use of Ni nanoparticles, function as active sites for the electrocatalytic CO₂ reduction reaction to CO.

Traditional electrocatalysts cannot effectively initiate this reaction due to the competing hydrogen evolution reaction, which takes precedence over the CO₂ conversion reaction. The Ni single atomic sites present a high CO selectivity of 95 percent under an overpotential of 550 mV in water, and an excellent stability over 20 hours’ continuous electrolysis. The anion membrane electrode assembly prevented the direct contact between the catalyst and liquid water, maximally suppressing the hydrogen evolution side reaction and facilitating the CO₂ mass transport.

Scanning transmission electron microscopy and beamline 8-ID at U.S. Brookhaven National Laboratory were used to characterize the material and the reactions. The researchers observed that single Ni atoms catalyzed the CO₂ conversion reaction with a maximum 97 percent selectivity, and say this is a major step toward recycling CO₂ for usable energy and chemicals.

Scientists from Harvard University, Stanford University, University of Science and Technology of China, University of Saskatchewan (Canada) and U.S. Brookhaven National Laboratory participated in this research.