Single-atom catalysts (SACs), thanks to the higher density of exposed catalytic sites, can provide high selectivity and and efficiency as well as the suppression of the competing reactions. We have explored different SACs based on Fe,[1] Ni [2] and a combination of both [3].
First of all, we proposed the use of a C2N framework (a carbon nitride-based 2D layered nanostructure) loaded with atomically and uniformly dispersed iron (Fe/C2N) as a host material for the sulfur in a lithium-sulfur battery cathode.[1] C2N shows excellent electrical conductivity and is a highly porous and high surface area framework. The iron atoms trapped in the pores improve the ability of the cathode material to immobilize the soluble polysulfides and promote the reaction kinetics between sulfur, polysulfides and lithium sulfide.
Secondly, we tuned the electronic environment of atomically dispersed Ni-based 2D organic framework catalyst through the modification of their edge coordination toward alcohol electrooxidation.[2] We demonstrated that such nickel-based organic frameworks, combined with carbon nanotubes, exhibit outstanding catalytic activity and durability toward the oxidation of methanol, ethanol, and benzyl alcohol. The work not only introduced a new atomically dispersed Nibased catalyst, but also demonstrates a new strategy for designing and engineering highperformance catalysts through the tuning of their chemical environment.
Finally, we designed a new double-metal catalyst, presenting nearby nickel and iron active sites, which improved both efficiency and selectivity of the carbon dioxide (CO2) reduction reaction.[3] This configuration, provides excellent selectivity to CO2 evolution, boosting absorption and desorption of intermediates in the reduction process, and guarantees a low overpotential, which leads to less energy consumption. In addition, undesired competing reactions are strongly limited. Furthermore, the combination of Ni and Fe active sites demonstrated to act as a nano-reactor, since multistep reactions take place simultaneously with an improved overall activity and selectivity.
