Enhanced Conductivity and CO ₂ Activation in Li-Doped 2D Polyaramid: A DFT Study on the Electronic Structure and Catalytic Performance

Two-dimensional polyaramid (2DPA), a recently synthesized lightweight 2D material, exhibits a robust polymeric framework with conjugated aromatic rings and amide linkages, offering exceptional chemical stability, mechanical strength, and a high surface area with abundant active sites. These properties make 2DPA a promising candidate for catalytic applications in harsh environments. Using density functional theory (DFT), we systematically investigate lithium (Li)-doped 2DPA for the electrochemical CO2 reduction reaction (CO2RR). Our findings reveal that Li preferentially occupies the edge oxygen site with a strong adsorption energy of −3.23 eV, enhancing charge transfer and catalytic activity. Ab initio molecular dynamics (AIMD) confirms the thermal stability of Li-doped 2DPA. The CO2RR mechanism proceeds via key intermediates (*COOH, *OCOH, *OCHOH, and *CO), with a significantly lower *COOH formation barrier (1.31 eV) compared to graphene. The favorable *COOH → *CO transition (−0.60 eV) facilitates efficient conversion of CO2. The stability of *CO and *OCH3 intermediates enables selective methane and methanol production, while energy peaks at *COOH and *CHO mark critical transition states. These insights establish Li-doped 2DPA as a highly efficient and durable electrocatalyst for CO2 reduction, advancing the development of sustainable CO2RR technologies.