Utilizing Benign Oxidants for Selective Aerobic Oxidations Using Heterogenized Platinum Nanoparticle Catalysts

Abstract

Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. By using platinum nanoparticle catalysts that are generated in situ by extrusion from a porous copper chlorophosphate framework, the role of oxidants in the selective oxidation of benzyl alcohol to benzaldehyde was evaluated, with a view to establishing structure-property relationships. With a detailed study of the kinetic properties of the oxidation reaction, it has been determined that the aerobic oxidation pathways progress with lower levels of product selectivity and higher activation energies (72.4^-1) than the peroxide-based ones (23.6^-1); affording valuable insights in the design of solid catalysts for selective oxidation reactions. Furthermore, through the use of X-ray absorption spectroscopy, the effect of calcination temperature on the degree of extrusion and its influence on nanoparticle formation have been evaluated, leading to the establishment of structure-activity correlations between the observed activation energies and the proportion of nanoparticle species generated. Tuned cats.: Well-defined platinum nanoparticles are generated in situ by anion extrusion within porous framework architectures (see figure). In these catalysts the local structural environment of the active site is controlled by the calcination conditions, and thus industrially significant, sustainable catalytic oxidation reactions are possible with tert-butyl hydroperoxide (TBHP) or oxygen.