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

Background: The 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. Methods: In 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 findings: The 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/SBA15 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.