Conjugated polyimides modified self-supported carbon electrodes for electrochemical conversion of CO2 to CO

Abstract

The electrochemical reduction of carbon dioxide (CO2RR) offers a promising approach to address the dual challenges of energy scarcity and environmental degradation. This study presents a new, cost-effective, and scalable electrocatalyst: self-supporting carbon paper modified with porous conjugated polyimides. This innovative material facilitates efficient CO2 conversion in aqueous media, eliminating the need for a pyrolysis step. The electrocatalyst’s design utilizes a non-metallic organic polymer with a high density of nitrogen atoms, serving as active sites for catalysis. Its unique mesoporous microsphere structure comprises randomly stacked nanosheets that are generated in situ and aligned along the carbon fibers of carbon paper substrate. This architecture enhances both CO2 adsorption and ensures proper electron transportation, facilitated by the conjugated structure of the polymer. Additionally, the inherent hydrophobicity of conjugated polyimides contributes to its robust catalytic performance in selectively reducing CO2, yielding CO as the primary gaseous product with up to 88.7% Faradaic efficiency and 82.0 mmol g-1 h-1 yield rate. Therefore, the proposed electrocatalyst provides a sustainable solution for electrochemical CO2RR catalyzed by non-metal organic materials, combining high efficiency with the advantages of a simple preparation process and the absence of costly materials or steps. This research contributes to the advancement of CO2RR technologies, potentially leading to more environmentally friendly and energy-efficient solutions.