2D Covalent Metals: A New Materials Domain of Electrochemical CO2Conversion with Broken Scaling Relationship.
Toward a sustainable carbon cycle, electrochemical conversion of CO2into valuable fuels has drawn much attention. However, sluggish kinetics and a substantial overpotential, originating from the strong correlation between the adsorption energies of intermediates and products, are key obstacles of electrochemical CO2conversion. Here we show that 2D covalent metals with a zero band gap can overcome the intrinsic limitation of conventional metals and metal alloys and thereby substantially decrease the overpotential for CO2reduction because of their covalent characteristics. From first-principles-based high-throughput screening results on 61 2D covalent metals, we find that the strong correlation between the adsorption energies of COOH and CO can be entirely broken. This leads to the computational design of CO2-to-CO and CO2-to-CH4conversion catalysts in addition to hydrogen-evolution-reaction catalysts. Toward efficient electrochemical catalysts for CO2reduction, this work suggests a new materials domain having two contradictory properties in a single material: covalent nature and electrical conductance.
Graduate School of Energy, Environment, Water and Sustainability (EEWS), Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-Ro, Yuseong-Gu, Daejeon 34141, Korea.
Hyeyoung
H
Shin
Graduate School of Energy, Environment, Water and Sustainability (EEWS), Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-Ro, Yuseong-Gu, Daejeon 34141, Korea.
Yoonhoo
Y
Ha
Graduate School of Energy, Environment, Water and Sustainability (EEWS), Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-Ro, Yuseong-Gu, Daejeon 34141, Korea.
Hyungjun
H
Kim