Selective oxidation of alkenes catalyzed by palladium-based bimetallic heterogeneous catalysts under atmospheric pressure

Abstract

Pd-based bimetallic catalysts were prepared through impregnation and high-temperature hydrogen reduction. The newly prepared catalysts were characterized by XRD, TEM, HR-TEM and XPS, and evaluated in a reaction system for the Wacker oxidation of alkenes. A series of alkenes were oxidized to corresponding ketones in the presence of the new catalyst under the synergistic oxidation of tert-butyl hydrogen peroxide (TBHP) and air. The stability of the catalyst and the heterogeneity of the reaction system were also investigated by catalyst recycling and hot-filtration tests. The performance of the catalyst was correlated with the interaction between Pd and Cu, as well as metals and the support. The synergistic effect of TBHP and air was confirmed in the reaction. The Wacker-type oxidation of alkenes (including aryl alkenes and cycloalkene) was achieved in the developed system. The yields of the low-carbon alkenes and cycloalkanes need to be improved.