Ricky Andi Syahputra, Muhammad Irvan, Andriayani Andriayani, Basuki Wirjosentono, Karna Wijaya, Shiplu Sarker, Saharman Gea
Biochar, a carbon-rich material derived from biomass, has emerged as a promising catalytic platform owing to its low cost, wide availability, structural tunability, and environmental compatibility. This review provides a critical and mechanistically integrated assessment of biochar-based catalysts for sustainable hydrogen production across thermochemical and photochemical pathways. Rather than cataloging reported yields, the analysis adopts a standardized normalization framework, expressing hydrogen productivity primarily as mmol H₂ g⁻¹ catalyst h⁻¹ to enable reliable cross-study comparison. The review introduces a unified structure–property–performance perspective linking feedstock chemistry, activation strategy, and metal–carbon interactions to pathway-specific hydrogen productivity. Evidence indicates that feedstock-derived chemistry often exerts a stronger influence on catalytic behavior than pyrolysis temperature alone, while controlled metal doping—particularly with Ni, Fe, and Co—enhances active-site accessibility and stability. Activation treatments modulate porosity and surface functionality, yet excessive modification may induce structural degradation or catalyst deactivation. Beyond catalytic efficiency, biochar-based systems offer sustainability advantages through biomass valorization, reduced reliance on critical raw materials, and compatibility with circular carbon strategies. By integrating mechanistic insight, normalization rigor, and sustainability considerations, this review positions biochar not merely as a low-cost alternative support, but as a tunable catalytic platform for next-generation hydrogen technologies. © 2026, Walailak University. All rights reserved.
Postgraduate School, Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Sumatera Utara, Medan, 20155, Indonesia; Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Negeri Medan, Medan, 20221, Indonesia; Cellulosic and Functional Materials Research Centre, Universitas Sumatera Utara, Medan, 20155, Indonesia; Department of Chemistry, Faculty of Mathematics and Natural Sciences, Gadjah Mada University, Yogyakarta, 55281, Indonesia; Department of Civil and Manufacturing Engineering, Faculty of Engineering, Norwegian University of Science and Technology, NTNU, Gjøvik, 2815, Norway
