Changes in properties and mechanism of poly(p-phenylene terephthalamide) activated carbon paper prepared by different activation methods

Abstract

Activated carbon paper is a type of porous carbon material with a highly developed pore structure and a large specific surface area. It finds extensive applications in adsorption, complexation, and catalyst support. To prepare high-performance activated carbon paper, this study investigates the changes in performance and structure of Poly(p-phenylene terephthalamide) (PPTA) paper under CO₂ activation, ZnCl₂ activation, H₃PO₄ activation, and NaOH activation conditions. The research reveals that carbon paper after CO₂ activation has a certain tensile strength (0.36 MPa), while chemically activated carbon paper lacks tensile strength. Incorporating 15% carbon fiber (CF) into PPTA paper increases the tensile stress (1.26 MPa) and tensile strain (4.18%) of the activated carbon paper. NaOH-activated carbon paper has the highest specific surface area (1321.6 m²/g), the most disordered carbon structure (I_D/I_G = 1.22), the lowest carbon yield (23.9%), and a pore rate 4.16% higher than that of CO₂-activated samples. The activated carbon paper prepared by ZnCl₂ activation has the highest content of C = N bonds, with the nitrogen content of pyridine increasing by 31.8% compared to CO₂ activation. This indicates that ZnCl₂ protects the N elements in PPTA paper during the activation process, preventing their decomposition during carbonization. The activated carbon paper prepared by H₃PO₄ activation has the lowest electrical conductivity (1.62 S/cm).