Conversion of Xylose to Furfural Catalyzed by a Nb/Carbon Nanotube

Developing solid acid catalysts with high efficiency and robust recyclability remains a critical challenge in sustainable furfural production. In this study, a Nb/carbon nanotube (Nb/CNT) catalyst was synthesized via defect, enabling the anchoring of niobium oxide nanoparticles onto carbon nanotubes (CNTs) via covalent C–O–Nb bonds at sp3-hybridized defect sites. This unique coupling mechanism, combined with the mesoporous structure of a carbon nanotube, effectively confines and stabilizes the active Nb species, even at a low loading of 2 wt %. The optimized catalyst achieved a notable furfural yield of 90.5% in a H2O/toluene biphasic system, outperforming most reported solid acid catalysts. Furthermore, it retained 84.6% of its initial activity after 20 consecutive cycles, demonstrating exceptional stability attributable to the synergistic effects of defect anchoring and mesoporous confinement. This work provides a paradigm for designing durable catalysts through the precise defect-mediated stabilization of active sites.