A Comprehensive Review on Chemical Process and Catalytic Mechanism in Conversion of Biomass to Carbon Materials

Abstract

Biomass, the Earth’s largest reservoir of renewable reduced carbon, presents a unique opportunity to reshape global energy and materials systems through inherently carbon-neutral chemistry. Its complex and heterogeneous composition-woven from cellulose, hemicellulose and lignin-necessitates catalytic approaches that can navigate selective bond rearrangements while directing deoxygenation, aromatization and carbon-framework evolution. This review article provides a comprehensive perspective on modern biomass conversion strategies, encompassing hydrothermal carbonization, pyrolysis, gasification, liquefaction and hybrid biochemical routes. We examine the mechanistic principles that govern thermal breakdown and catalytic upgrading, focusing on how engineered acid-base environments, metal-support interactions and electronic-structure tuning drive C–O, C–C and C–N transformations. Emerging process-intensified technologies, such as microwave-assisted reactors, plasma-enabled systems and super- or subcritical-water platforms, are also discussed for their ability to alter reaction kinetics, lower activation barriers and construct carbon architectures with controlled porosity and graphitic order. By linking feedstock composition to product distributions and carbon functionality, we identify overarching structure–performance relationships that unify otherwise distinct conversion pathways. We conclude by outlining persistent challenges-including catalyst deactivation by heteroatom-rich feeds, variability in biomass composition, tar formation and the need for integrated reactor-catalyst designs, and highlight research opportunities that could accelerate the translation of biomass-derived carbon materials from laboratory studies to industrial-scale implementation.