PtZn alloy supported on functionalized carbon nanotubes for glucose oxidation at room temperature

The selective oxidation of glucose to value-added acids is pivotal for biomass valorization, yet achieving high activity and selectivity at room temperature with air as the sole oxidant remains challenging. Herein, PtZn alloy nanoparticles dispersed on surface-functionalized carbon nanotubes (CNTs) are developed for aerobic glucose oxidation under ambient conditions. The –COOH–enriched catalyst (PtZn/CNT-COOH) exhibits the highest performance, delivering a 94.5 % total-acid yield at 25 °C within 120 min in air, while hydroxyl-functionalized and unmodified supports show markedly lower efficiencies under identical conditions. The catalyst retains activity over repeated cycles, indicating robust stability. Comprehensive surface chemistry analyses verify the preservation and enrichment of –COOH groups, which enhance interfacial hydrophilicity and promote substrate capture. Complementary theoretical calculations indicate strengthened glucose adsorption and facilitated formyl C–H activation on PtZn/CNT-COOH relative to the other supports, accounting for its superior kinetics and selectivity. This work establishes a mild, air-breathing route to gluconic acid and provides a clear structure-function basis for designing COOH-directed supported catalysts for selective carbohydrate oxidations.