Impact of Na at the low temperature Fe catalysis on high quality cellulose-based graphitic carbon

Biomass-based graphitic carbon is a promising material, but the effect mechanism of inherent alkali metals on the catalytic pyrolysis of biomass is still unclear. In this study, cellulose was selected as the model substance, and the influence mechanism of Na on the graphitization of cellulose catalytic pyrolysis was investigated through a combination of experiments and theoretical calculations. The results indicate that Na can interact with the carbon skeleton through van der Waals forces, thereby altering the spatial structure of graphite crystals and increasing the interlayer spacing of graphite by 27.7%. In addition, Na can coexist with Fe(III) in the form of oxides, and it can also increase the reaction energy barrier of reverse hydroxylation and dehydration cyclization, reducing the generation of reducing gases mainly composed of CO. This will hinder the reduction of iron-based catalysts, thereby affecting the formation of the graphite microcrystalline structure. The research results suggest that controlling the ratio of Na content to iron-based catalysts within a 1:1 range is more conducive to the preparation of cellulose-based graphitic carbon.