Nanocatalyst-enabled waste-to-energy systems: from material innovation to techno-economic and sustainability pathways

Abstract The accelerated proliferation of industrial, agricultural, and municipal waste, in conjunction with the escalating global demand for energy, underscores the imperative for sustainable waste-to-energy (WtE) methodologies. This review scrutinizes contemporary advancements in nano-engineered catalysts that augment the selectivity, kinetics, and energy recovery associated with the conversion of waste into hydrogen, syngas, and value-added fuels. Attention is directed towards a variety of catalyst categories, including single-atom catalysts, metal-organic framework (MOF)-derived structures, biomass-derived carbon nanomaterials, and plasmonic nanoparticles, as well as their synthesis utilizing waste precursors. Unlike previous reviews, this investigation combines nanoscale catalyst design with techno-economic evaluations, environmentally friendly synthesis methodologies, and artificial intelligence (AI)-driven optimization, thereby offering a comprehensive perspective that interconnects material innovation with system-level sustainability. Documented advancements reveal energy recovery efficiencies exceeding 80 %, hydrogen Faradaic efficiencies of over 95 %, and recyclability rates above 90 % under realistic conditions. Furthermore, life-cycle assessments, benchmark performance indicators, and comparative techno-economic analyses are provided to exemplify the scalability of nano-enhanced WtE. Constraints, including catalyst deactivation, nanoparticle toxicity, and hurdles in large-scale synthesis, are critically evaluated, alongside prospective avenues in hybrid solar-electrochemical systems and digital twin-assisted process management. This scholarly work presents a distinctive roadmap that positions nano-enabled WtE as a fundamental element of the circular hydrogen economy.