Effect of acid treatment on structure and morphology of carbons prepared from pyrolysis of polyfurfuryl alcohol

Abstract

Furfuryl alcohol (FA) was polymerized in aqueous solutions consisting of polyvinyl pyrrolidone (PVP) as a surfactant together with hydrochloric acid, phosphoric acid, or acetic acid as a catalyst, respectively. The polymerization degree of FA and the resulting structural difference after carbonization were examined. Experiments revealed that the presence of acids does indeed promote polymerization of FA, leading to a reduced defect population and an eventual formation of a more ordered structure in the carbonized products. This is particularly pronounced when hydrochloric acid was used as a catalyzer, forming “nonstick” polyfurfuryl alcohol (PFA) particles with a diameter ca. 0.5–1 μm. The polymeric particles were then converted into microporous carbon spheres with a specific surface area of 297 m2/g when calcined at 600 °C in argon atmosphere. On the contrary, FA in the rest of catalyst systems showed aggregated form with a pronouncedly reduced specific surface area ranging from 0.3 to 5.2 m2/g.