Influence of metal loading and temperature on methane decomposition and nano-carbon formation over iron catalyst supported by sawdust biochar and alumina

Abstract

This study investigates the methane conversion by Fe catalyst supported on alumina and sawdust biochar (SBC) at three different temperatures (900 °C, 800 °C, 700 °C) and Fe loading (5 %, 10 %, and 15 %) and analysis of carbon nanotube formation. The results indicate that both the support material and Fe loading significantly influenced the methane conversion. XRD analysis confirmed successful incorporation of Fe species on alumina and sawdust biochar supports, where SBC-supported catalysts exhibited improved Fe dispersion and lower crystallite growth. SBC-supported catalysts demonstrated higher and more stable methane conversion across all temperatures compared to alumina-supported catalysts. Notably, loading of 10 % Fe on SBC exhibited the highest sustained performance, maintaining near-complete H2 production (>85 %) over experimented durations and supporting multiwall carbon nanotube formation at high temperature. Temperature positively affected the reaction rate, with higher temperatures correlating with enhanced methane conversion. The microstructural evaluation performed through TEM and Raman spectra analysis revealed the formation of multi-walled carbon nanotubes with graphitic walls, displaying morphological diversity and variations in tube diameter. Copyright © 2026. Published by Elsevier Ltd.