2D carbon nanotubene and its hetero-bimetal-contain derivatives: A new family of carbon allotropes for promoting CO2 reduction

Electrocatalysts are crucial for the electrochemical conversion of CO2 into valuable chemicals. By employing density functional theory calculations, this study introduces the novel carbon nanotubene (CNTene), a single-layer two-dimensional lattice of cross-linked carbon nanotubes, and explores its potential in the CO2 conversion. The semi-metallic nature with multiple Dirac points was identified for CNTene. Key findings reveal that while pristine CNTene exhibits modest catalytic activity, the incorporation of hetero-bimetallic catalytic sites significantly improves the electrocatalysis of CO2, notably outperforming competing reactions. This enhancement is evidenced by a reduction in the Gibbs free energy for *COOH formation to an average of 3.2 eV when hetero-bimetallic active sites are present and the achievement of a minimum CO2 reduction limiting potential of −0.63 V for Ni-Mn@CNTene. Furthermore, a strong correlation was identified between the charge transfer of metal atoms in active sites and reaction limiting potentials, highlighting the superior performance of hetero-bimetallic configurations.