Sinter-resistant platinum nanocatalysts immobilized by biochar for alkane hydroisomerization

Abstract

A biochar-assisted strategy for the synthesis of supported metal nanocatalysts with immobilized Pt nanoparticles (NPs) is devised, in which Pt NPs are encapsulated with a rigid dense carbon film to enhance their sintering resistance. Since the carbon film limits the migration of individual metal particles, a Pt island is eventually formed, and the metal–support interactions are dramatically improved. The variable morphology of the Pt island during the heating process was observed by in situ TEM, and the structure remained stable up to 700 °C. The surface-bound biochar and hydrogen atmosphere produce a synergistic effect of reduction, which is conducive to the formation of reductive Pt NPs. The catalysis of n-dodecane hydroisomerization at high temperature showed excellent performance achieving a maximum isomer yield of 80%. The facile synthetic approach could be expanded to the stabilization of other NPs supported on extensive supports, providing a general strategy for enhancing the sintering resistance and thermostability of metal NPs on supported metal catalysts.