Low temperature catalyst-assisted pyrolysis of polymer precursors to carbon

Abstract

The aim of this work is to study the pyrolysis of polymer precursors to carbon at lower temperatures using a catalyst. We have added different weight ratios of nickel acetate tetrahydrate (NiAc) and multi-walled carbon nanotubes (MWCNTs) as catalysts into two different precursors, polyacrylonitrile (PAN) and resorcinol-formaldehyde (RF), separately. PAN composite was stabilized whereas RF composite was dried under sub-critical conditions followed by pyrolysis carried out at different temperatures. To examine the effect of pyrolysis temperature and catalyst concentration, PAN-and RF-derived carbons were characterized by elemental analysis, X-ray diffraction, Raman spectroscopy, transmission electron microscopy, Fourier transform infrared spectrophotometer and small angle X-ray scattering, respectively. It was found that addition of NiAc facilitated similar carbon yield at much lower temperature than what was obtained without a catalyst. The addition of MWCNTs enhanced the crystallinity of carbon samples, which is otherwise possible only by higher heat treatment. This study clearly suggests adopting catalyst-assisted less energy intensive low temperature pyrolysis for polymer precursors to carbon with better yield as well as crystallinity.