Biomass conversion to second‐ and third‐generation biofuels: recent developments

Abstract The growing uncertainty surrounding fossil fuel depletion, coupled with volatile market dynamics, is accelerating the shift toward sustainable technologies. Second‐ and third‐generation biofuels have emerged as promising alternatives to first‐generation biofuels, eliminating competition with food resources and offering improved environmental compatibility. However, their widespread adoption faces persistent bottlenecks, including low conversion yields, feedstock recalcitrance, high processing costs, catalyst deactivation, and limited scalability of innovative systems. This review addresses these challenges by presenting recent advances in catalytic processes for converting both lignocellulosic (second‐generation) and aquatic (third‐generation) biomass into biofuels. Emphasis is placed on novel catalytic approaches, such as heterogeneous, biocatalytic, nanocatalytic, and ionic liquid‐based systems, as well as innovative feedstocks and process intensification strategies. The article contributes a comprehensive cross‐comparison of catalytic pathways, highlights conversion mechanisms, and outlines emerging solutions to overcome technological and economic barriers. By identifying current gaps and future directions, this review aims to support the development of more efficient, sustainable, and industrially viable biofuel production platforms.