Toward biomass-based single-atom catalysts and plastics: Highly active single-atom Co on N-doped carbon for oxidative esterification of primary alcohols

Abstract Supported single-atom catalysts (SACs) have attracted much attention as their advantageous performances in heterogenous catalysis. Here, we report a general synthesis approach to produce SACs on nitrogen-doped carbon (M SAs-N@C, where M = Fe, Co, Ni, Cu) by engineering bioinspired metal-lignin coordination complexes. The Co SAs-N@C catalyst shows extraordinary reactivity for the oxidative esterification of primary alcohols via aldehyde intermediates, achieving a high turnover frequency (TOF, 55.6 mol methyl benzoate  mol −1 Co  h −1 ) for benzyle alcohol, which is approx. 18 times of Co nanoparticles. Experiments and theoretical calculations reveal that the atomically dispersed Co species in Co SAs-N@C are active sites for this reaction. As a proof-of-concept, we demonstrate an integrated biorefinery that lignin-based catalyst enables the effective transformation of carbohydrate-derived furans into building block of plastics and fragrance. Our technique not only provides a facile, low-cost and scalable method to atomically dispersed catalysts but also opens new avenue toward lignin valorization and biomass economy.