Hierarchically ordered porous carbon with atomically dispersed cobalt for oxidative esterification of furfural†

Nitrogen-rich zeolitic imidazolate frameworks (ZIFs) are ideal precursors for the synthesis of metal single atoms anchored on N-doped carbon. However, the microporous structures of conventional ZIFs lead to low mass transfer efficiency and low metal utilization of their derivatives. Here, we construct a composite of Co single atoms anchored on nitrogen-doped carbon with a three-dimensional ordered macroporous structure (Co-SA/3DOM-NC) by two-step pyrolysis of ordered macro/microporous ZnCo-ZIF. Co-SA/3DOM-NC shows high activity in the oxidative esterification of furfural, achieving a 99% yield of methyl 2-furoate under mild reaction conditions, which is significantly superior to the microporous and the Co-nanoparticle counterparts. The high activity of Co-SA/3DOM-NC should be attributed to the CoN₄ centers with high intrinsic activity and the ordered macroporous structure, promoting the mass transfer of reactants and accessibility of active sites.

Keywords: Heterogeneous catalysis; Hierarchical pores; Ordered macropore; Oxidative esterification reaction; Single-atom catalysts.