Biochar-based green nickel catalyst from Persea americana seed waste: a sustainable approach to supported metal...

This study demonstrates the valorization of Persea americana (avocado) seed waste into a high-performance, biochar-based green catalyst for sustainable biofuel production. Activated biochar (ABC) was produced via KOH activation and utilized as a support for nickel-active species. Nickel was loaded through incipient wetness impregnation, followed by thermal reduction at 400 °C to transition NiO to metallic Ni⁰. KOH activation significantly enhanced the support's textural properties, increasing surface area to 584 m²/g and pore volume to 0.327 cm³/g. XRD and FTIR analyses confirmed the formation of a turbostratic carbon framework and the successful anchoring of face-centered cubic (fcc) metallic nickel. The resulting 10rNi/ABC catalyst featured a mesoporous architecture (average pore diameter 6.93 nm), which is critical for mitigating mass-transfer limitations during the processing of bulky triglycerides. The synergy between the defect-rich carbon support and well-dispersed nickel nanoparticles yielded a stable, highly active catalyst for hydrodeoxygenation. This research provides a circular economy framework for transforming agricultural residues into high-value materials for green energy applications.