Lignin-Derived Thin-Walled Graphitic Carbon-Encapsulated Iron Nanoparticles: Growth, Characterization, and Applications

Biorenewable lignin has been used as a precursor to produce varieties of carbon materials. However, up to now, it has not been easy to obtain graphitic carbon-encapsulated metal materials without a high-temperature process. Here, we demonstrate an antiprogrammed temperature pyrolysis route for the fabrication of iron encapsulated in thin-walled graphitic layers with a low temperature. The industrially available lignin was used as a biorenewable carbon source, and ferric nitrates were used as metal sources. We found that the pyrolysis process during carbonization is a critical factor to obtain thin-walled graphitic carbon-encapsulated iron materials. When the pyrolysis process is adjusted, the size of iron particles is readily tunable, and more importantly, the iron particles are wrapped in one to four layers of graphitic carbon. The thin-walled graphitic carbon-encapsulated iron material from biorenewable lignin sources is a good candidate for Fischer–Tropsch synthesis to lower olefins catalyst.