Study on the structural properties and CO2 reduction mechanism of Cu13 nanoparticles supported on carbon nanotubes and defective graphene

Abstract

In this study, density functional theory (DFT) was employed to investigate the structural and electronic properties of Cu₁₃ nanoparticles supported on defective graphene and carbon nanotubes. Stable catalyst models were optimized, and the stability was assessed via ab initio molecular dynamics (AIMD) simulations. The structural features, charge distribution, and CO₂ adsorption behaviors on both catalysts were systematically analyzed. Furthermore, differential charge density and density of states (DOS) analyses were used to elucidate the correlation between the catalysts’ structural/electronic characteristics and their catalytic activity. Three possible reaction pathways for CO₂ reduction were examined for each catalyst. By comparing the activation energies along different pathways, the optimal reaction routes for the formation of four distinct C₁ products from CO₂ reduction were identified. For both catalysts, the most favorable pathway for CO formation was *CO₂ → *COOH → *CO. The defective-graphene-supported Cu nanoparticles exhibited enhanced CO₂-to-CO conversion efficiency, indicating superior catalytic activity. The optimal reaction pathway for HCOOH production on both catalysts was found to be *CO₂ → *COOH → *HCOOH. Both catalysts facilitated the formation of HCOOH, showing high catalytic activity toward this product. The defective-graphene-supported Cu nanoparticles favored the formation of CH₃OH, while the carbon-nanotube-filled Cu₁₃ catalysts were more conducive to CH₄ production. Overall, the defective-graphene-supported catalyst exhibited higher catalytic activity for CO₂ reduction compared to its carbon-nanotube counterpart. These findings aim to provide theoretical guidance for the design and optimization of thermocatalysts for CO₂ reduction.