Enhancing the stability of a cobalt-based Fischer–Tropsch synthesis catalyst using g-C3N4-coated SBA-15 as support

Abstract

BackgroundThe design and synthesis of catalysts with high stability, activity and selectivity in Fischer–Tropsch synthesis (FTS) have been attracting extensive research attention. Maintaining high catalytic stability and activity is the best strategy for improving the catalyst efficiency and economic benefits. MethodsIn this study, graphitic carbon nitride (g-C3N4)-coated SBA-15 was utilised as a support material to prepare cobalt-based FTS catalysts. The catalysts coated with g-C3N4 were studied via TEM, XPS, XRD, H2-TPR, TG, N2 adsorption–desorption, and tested in a fixed-bed reactor. Significant findingsThe catalysts coated with g-C3N4 were considerably more stable than the Co/SBA-15 catalyst without g-C3N4 coating during a 100 h test period. Furthermore, the CO-conversion performance of the Co/SBA-15 catalyst decreased continuously. Notably, the activity of the Co/SBA-15@0.5C3N4 catalyst with a low g-C3N4 loading was higher than that of the Co/SBA-15@1C3N4 catalyst with a relatively high g-C3N4 loading. g-C3N4 can significantly strengthen the interaction between the cobalt species and the support, thereby increasing the catalyst stability. Therefore, a highly stable catalyst with good activity can be achieved by employing a small amount of g-C3N4 for surface modification. The results highlight the effectiveness of the proposed strategy for preparing highly stable, cobalt-based catalysts with good activity.