Enhancing the catalytic performance of Co-N-C derived from ZIF-67 by mesoporous silica encapsulation for chemoselective hydrogenation of furfural.

Abstract

Developing Cr-free and non-noble metal catalysts with high activity, selectivity and durability for chemoselective hydrogenation of furfural to furfuryl alcohol is highly desirable yet challenging. In this study, we design a hollow mesoporous Co-N-C@mSiO2 nanostructure derived from ZIF-67 via the encapsulation-pyrolysis strategy. The Co-N-C@mSiO2 catalyst exhibits excellent catalytic performance in the furfural hydrogenation towards furfuryl alcohol with good stability, and is much better than the Co-N-C catalyst originating from plain ZIF-67 and other reported transition metal catalysts. Characterization methods and control experiments show that Co-Nx species rather than Co metal should be catalytically active sites for the above reaction. The enhanced performance is associated with abundant Co-Nx active sites, good mass transport, and the SiO2 shell protection. This work provides a novel and facile strategy for preparing highly efficient non-precious metal catalysts to replace Cr-based and noble metal catalysts for furfural hydrogenation.