Selective Oxidation of Aromatic Alcohols to Aldehydes Catalyzed by HKUST-1-Derived Cu-Based Carbon Material and TEMPO
A Cu-based carbon catalyst (H-Cu/C) with octahedral morphology was synthesized by pyrolyzing the metal-organic framework (MOF) precursor HKUST-1 under inert N2 atmosphere. Characterization via XPS, XRD, SEM, and HRTEM revealed that Cu(0) nanoparticles were uniformly dispersed in a carbon matrix, with island-like Cu2O structures serving as active sites. The carbon matrix effectively stabilized the metal nanoparticles, suppressing migration and sintering during reaction. Combined with TEMPO and using molecular oxygen as a green oxidant, the H-Cu/C catalyst exhibited high efficiency in the selective oxidation of aromatic alcohols to corresponding aldehydes under alkali-free conditions. Using benzyl alcohol as a model substrate, an alcohol conversion of 99.2% and a benzaldehyde yield of 94.1% were achieved under mild conditions (100 °C, 0.5 MPa O2, 1 h). The catalytic system demonstrated excellent universality for various mono- and ortho/para-disubstituted aromatic alcohols, affording conversions over 99% and aldehyde yields above 95%. The catalyst could be regenerated via H2 reduction and reused without significant loss of activity. This work provides a new strategy for designing green and efficient non-noble metal catalytic systems for oxidation reactions.