Asymmetric coordination engineering of active centers in MXene-based single atom catalysts for high-performance ECO2RR

Abstract

Asymmetric coordination effect is an important concept in heterogeneous catalysis where both catalytic activity and product selectivity are serious influenced. However, this effect has rarely been understood because of the difficult in characterizing detailed coordination information. Here, by employing a theoretical study on electrocatalytic CO2 reduction reaction (ECO2RR) towards HCOOH over Ti3C2O2-based NS/NN co-coordinated transition metal single atom catalysts (TM-NS/NN-Ti3C2O2 SACs), we show that asymmetric coordination environments have great impact on the electronic structure of the active center. Both electron transferring ability and spin polarization of the active center are vital to optimize the adsorption and hydrogenation of key intermediates. As a result, both catalytic activity and product selectivity can be maximized. V-NN-Ti3C2O2 are predicted to promote high-throughput HCOOH generation process at operation applied potential of −0.32 with considerable electrochemical stability, surpassing most reported catalysts. This work demonstrates V-NN-Ti3C2O2 as high-performance ECO2RR catalysts, and highlights that the introduction of the concept of asymmetric coordination effect may offer a new insight into the rational design of more efficient SACs.