Journal of Catalysis, Vol.386, 60-69, 2020
Atomically decorating of MnOx on palladium nanoparticles towards selective oxidation of benzyl alcohol with high yield
Palladium nanoparticles are effective catalysts for selective oxidation of benzyl alcohol, which is a fundamental reaction in fine chemicals production. Herein, an atomic-scale oxide decoration catalytic structure is designed and implemented by atomic layer deposition (ALD). The MnOx/Pd catalysts fabricated by ALD show enhanced conversion and selectivity simultaneously, thus a high yield of benzaldehyde is obtained. Aiming to the difficulty in controlling reaction pathways and byproducts distribution, Pd (1 1 1) facets are selectively passivated by MnOx deposition. It is found that the byproduct toluene formation is completely suppressed. The proposed structure is also beneficial for inhibiting the decarbonylation reaction of benzaldehyde. On the other hand, the addition of MnOx via ALD realizes the modification of Pd electronic structure. The MnOx coated Pd nanoparticles forms reversed catalytic structure, which also creates large amount of highly active Pd-MnOx interfacial perimeters, result in improved catalytic activity and reaction rate. The TOF of MnOx decorated Pd catalyst reaches 31,561 h(-1), which is 8.7 times larger than that of the unmodified Pd catalyst. Meanwhile, the maximum conversion of benzyl alcohol and yield of benzaldehyde are improved to 84.7% and 76.5%, respectively. (C) 2020 Elsevier Inc. All rights reserved.