Nanostructured single-atom catalysts derived from natural building blocks

Single-atom catalysts (SACs) exhibit maximized atomic utilization with individual metal atoms anchored on supporting materials, where the pursuit of high performance and low cost presents challenges. In this case, carbon provides structural versatility and customizable properties as a supporting material, which has been extensively studied. Biomass materials have emerged as promising precursors for the preparation of carbon-based SACs due to their renewable nature for sustainability, abundance for low cost, and high carbon content for advanced performance. In this review, representative synthesis strategies and advanced characterization techniques for biomass-derived CS-SACs are summarized, which facilitate the establishment of guidelines for the rational design and fabrication of biomass-derived SACs. In addition, we provide a timely and comprehensive discussion on the use of a broad range of natural biomass for SACs, with insights into the specific carbon nature of biomass resources, including their carbon structures, metal-carbon coordination environment, and center metal species. Furthermore, the application areas of biomass-derived CS-SACs in various catalytic processes are reviewed. Overall, the challenges and future perspectives of using biomass as precursors for SACs are outlined. We hope that this review can offer a valuable overview of the current knowledge, recent progress, and directions of biomass-derived SACs.