A high active sites exposed hollow Co@SiO2 nanoreactor for high performance fischer–tropsch synthesis

Abstract

Optimizing catalyst geometry to break current limitations of Fischer-Tropsch synthesis (FTS) activity and the selectivity of long-chain hydrocarbons is a promising and challenging subject. Herein, a hollow Co@SiO2 catalyst with high dispersion of cobalt species anchored inside mesoporous hollow silica shell was successfully synthesized with the help of Co-metal organic framework materials, which displayed a surprisingly high C5+ hydrocarbons selectivity of 93.3% with a low methane selectivity of 3.4% at a remarkable high activity (CTY = 5.1 × 10-5 molCO gCo-1 s−1). The catalyst remained excellent stability for 200 h under industrially relevant conditions. The hollow core–shell structure provided an internal cavity environment that shortened the diffusion distance and contact area between Co metal and support, and improved exposed active cobalt sites and residence time of intermediates, inducing the growth of the catalytic activity and long-chain hydrocarbons selectivity. Protection of silica shell prevented the aggregation of active cobalt nanoparticles, further promoting the catalyst stability. This work provides a new insight into the design of high efficient and stable catalysts for FTS reaction.