Tailoring the microenvironment of MOF-derived Co nanoparticles for efficient higher alcohol production via Fischer-Tropsch synthesis

Abstract

Alcohols are considered as high value-added products from Fischer–Tropsch synthesis (FTS). Efficient conversion of syngas into higher alcohols (C2+OH, HA) is of great significance but poses grand challenges. Herein, a series of nitrogen-doped carbon confined Co catalysts (Co@NC and K-Co@NC) have been prepared via pyrolysis of different Co-containing ZIF-67 and K addition by ball milling. After K addition for modulation of the microenvironment of Co-containing catalysts, the K-Co@NC catalysts display an enhanced HA selectivity in FTS, with a maximum HA selectivity up to ∼30 % and a space time yield of HA (STYC2+OH) of 58 mg·gcat−1·h−1, reflecting the highest HA productivities for Co-based heterogeneous catalysts under similar FTS conditions. Comprehensive characterization studies reveal that K addition, could not only modulate the surface basicity for suppressing the side reactions, but also act as electron donors for promoting the formation of Co2C species during the FTS process, facilitating CO non-dissociative adsorption and CO insertion for improving alcohol formation in FTS. This work provides a feasible strategy for the design of highly efficient Co-based FTS catalysts for production of HA by utilizing MOF materials as the scaffolds.