Synthesis of Carbon-based Sorbent derived from Uncoated Groundwood Wastepaper using Al-Fe Catalyst for Hydrogen Storage

Abstract

The global energy crisis has accelerated the transition toward clean and sustainable energy sources, with hydrogen as a promising alternative fuel. The low energy density of hydrogen (~9.8 kJ/L) limits its practical storage, making material based physisorption, reversible and low energy as an alternative solution. Biomass-derived carbon offering renewability, low cost and tunable porosity. This study aims to synthesize and evaluate a metal-modified cellulose-derived carbon (WPDC) from uncoated groundwood wastepaper, sequentially coated with Al₂O₃ as a structural support and Fe(NO₃)₃·9H₂O as the iron precursor, then carbonized at 500 °C for 30 minutes under nitrogen flow. The resulting carbon material was characterized using FTIR, XRD, and SEM to investigate its chemical functionality, crystallinity, and surface morphology. Hydrogen adsorption tests conducted at 298 K showed capacity rising from 0.166 to 0.650 mmol g⁻¹ (0.033–0.130 wt%) as pressure increased from 1 to 3 bar. Equilibrium data conformed closely to the Freundlich isotherm, reflecting heterogeneous adsorption sites and relatively weak H₂–surface interactions, while kinetic analysis indicated pseudo-first-order behavior supported by intraparticle diffusion. Although the resulting capacity remains modest, these findings confirm that low-value wastepaper can be converted into a functional, metal-modified carbon adsorbent, offering a sustainable and economically viable pathway toward biomass-based hydrogen storage materials and identifying pore development as the primary target for future capacity enhancement.