Photoreforming and Photoelectroreforming of Waste-Derived Feedstocks for Solar-Driven Production of Fuels and Chemicals.

Photoreforming and photoelectroreforming have emerged as promising strategies for the solar-driven valorization of waste-derived feedstocks, offering a sustainable route to fuels and commodity chemicals. Unlike conventional thermochemical and biological processes, these photocatalytic and photoelectrocatalytic approaches operate under mild conditions, leveraging solar energy to activate complex organic substrates. Recent advances in artificial photosynthesis, including catalyst design, reaction engineering, and interfacial charge dynamics, have shown promise in improving selectivity and efficiency, yet fundamental challenges remain. Precise control over reaction pathways and suppression of undesirable side reactions remain difficult due to complex charge transfer kinetics, competing surface reactions, and limited stability under operational conditions. Addressing these challenges requires rational catalyst design to optimize charge transport, modulation of redox environments to enhance selectivity, and development of reactor architectures that maximize photon utilization and mass transfer efficiency. This review critically examines the mechanistic principles governing photocatalytic and photoelectrocatalytic waste valorization and discusses the central catalytic challenges. Finally, key challenges in process integration and scale-up are assessed, and future directions are outlined for practical implementation of photoreforming in circular carbon and hydrogen systems.