Carbon nanotube-supported Pt-based bimetallic catalysts prepared by a microwave-assisted polyol reduction method and their catalytic applications in the selective hydrogenation

Abstract

Platinum-based bimetallic catalysts supported on multi-walled carbon nanotube (CNT) were prepared by a facile microwave-assisted polyol reduction method (MAPR) and chemically probed in the selective hydrogenation of cinnamaldehyde. These bimetallic catalysts outperformed the catalysts prepared by the conventional impregnation method. CNT surface properties, selection of solvent and transition metal promoter were identified to be of great significance in tuning the catalytic performance. The best catalytic results were obtained on the Fe- and Co-modified Pt catalysts in the presence of ethyl acetate as the solvent after removing the oxygen-containing groups from CNT surfaces. Electrochemistry measurements including cyclic voltammetry and CO stripping, competitive hydrogenations of toluene and benzene, X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy were employed to gain insights into the physicochemical properties of catalysts. Both catalytic reactions and characterizations revealed that the MAPR method afforded close contact between promoters and platinum active sites, leading to superior catalytic properties.