Suppressing catalyst deactivation on Pd/CeO2 for selective oxidation of glucose into gluconic acid

Catalytic oxidizing of glucose into gluconic acid (GLUC) provides an attractive and feasible pathway for the high value-added utilization of glucose, in which Pd-based catalysts deliver outstanding catalytic performance. However, the surface poisoning of Pd caused by the strong adsorption of GLUC becomes the bottleneck for their further applications. Herein, oxygen-vacancy-riched ceria supported Pd catalyst (Pd/CeO2) is employed, which effectively alleviates the catalyst deactivation, and realizes high catalytic activity and stability with 100 % GLUC selectivity for glucose oxidation at room temperature. Kinetic analysis confirms the strong anti-poisoning ability of Pd/CeO2. The superior catalytic performance is attributed to the modulation of the electronic structure of Pd nanoparticles by the strong metal-support interaction between Pd and CeO2. The valence band photoemission spectra reveal that the downshift of the d-band center of Pd leads to the weak adsorption of GLUC on Pd/CeO2. Meanwhile, kinetic isotope effect experiments indicate that the OHads generated from H2O dissociation on the CeO2 surface affords another path for glucose oxidation, thus improves the catalytic activity. (c) 2022 Elsevier Inc. All rights reserved.