Nitrogen-Enriched Porous Polyacrylonitrile-Based Carbon Fibers for CO2 Capture

Abstract

Utilizing porous polyacrylonitrile (PAN) fibers as the precursors, porous carbon fibers were obtained by cross-linking of precursor fibers with hydrazine hydrate and subsequent heat treatment. A nitrogen content of more than 14 wt % was achieved in the carbon fibers. The porous carbon fiber that was prepared at low concentration of hydrazine hydrate (5 wt %) showed an optimal BET surface area of 277.4 m2/g with micro-/meso-/macropores. The CO2 adsorbed amount of this porous carbon fiber was 101 mg/g at 25 °C under atmospheric pressure, which was 2.1 times that of the fiber without cross-linking with hydrazine hydrate. In the simulated flue gas environment (10% CO2/90% N2), the adsorption capacity of the above-mentioned porous fiber was 32 mg/g at 25 °C, which was 1.4 times that of the fiber without cross-linking. These CO2 adsorption results demonstrated that the nitrogen functionalities and porous structure of the porous carbon fiber played an equivalent important role in the adsorption of CO2. The porou...