Rational Design of Heterogeneous Dual-Atom Catalysts for CO2 Electroreduction Reactions

One of the strategies to mitigate the concentration ofCO(2) in the atmosphere and reduce the global warming effectis to captureCO(2) and convert it to synthetic fuels and fine chemicals.Although CO2 is structurally and chemically stable, theelectrochemical transformation has attracted much attention becauseit offers mild reaction conditions regarding temperature, pressure,and process controllability. Among various electrocatalysts, dual-atomcatalysts (DACs) have been extensively developed in the past few yearsdue to their unique features for the electrochemical reactions ofsmall molecules. The catalytic activity of DACs in the electrochemicalCO(2) reduction reaction (eCO(2)RR) has surpassedsingle-atom catalysts (SACs) by providing a higher metal loading,two active sites (cf. one active site for SACs), a synergistic effectof adjacent metal atoms, the possibility of tuning the electronicstate (adjusting the d-band center), and more possible configurationmodes (side-on and side-bridge) for adsorption of CO2 (cf.only end-on and end-bridge modes for SACs). As a result, both higherreactivity and selectivity in eCO(2)RR can be achieved bybreaking scaling relationships with more possible interactions betweenintermediates and active sites. This review highlights and discussesthe recent progress in applying homo- and heteronuclear DACs for eCO(2)RR focusing on the synthesis, characterization, and electrochemicalcatalytic performance.