Redox-active coordination catalysts for selective thermochemical valorization of biowaste: Mechanistic insights and structure-performance relationships

The growing demand for renewable energy has intensified global efforts to transform biowastes into value-added fuels and chemicals rather than viewing them as disposal challenges. Derived mainly from lignocellulosic and other organic residues, these wastes are rich in carbon and reactive functional groups, making them promising feedstocks for thermochemical conversion via pyrolysis, gasification, and hydrothermal liquefaction. Yet, their compositional complexity, high oxygen content, and inorganic impurities remain major barriers to efficient transformation and catalyst durability. This review offers an integrated perspective on recent advances in the catalytic valorization of biowaste, with a particular emphasis on how coordination chemistry principles can enhance reaction selectivity and energy efficiency. Redox-active metal complexes, zeolites, and metal-organic frameworks are highlighted for their ability to mediate controlled bond activation and electron transfer during reforming and aromatization processes. By linking feedstock chemistry, pretreatment strategies, and catalytic mechanisms, this work establishes structure-activity-selectivity relationships that underpin syngas and aromatic production. Finally, emerging concepts such as AI-guided catalyst design, integration with circular bioeconomy frameworks, and dual-function redox systems, are discussed as promising pathways toward scalable, low-carbon, and sustainable energy technologies.