Activating nitrogen-doped carbon nanosheets by KOH treatment to promote the Fischer-Tropsch synthesis performance

Both appropriate support and promoter decoration are vital to improve the performance of Fe-based catalysts in Fischer-Tropsch Synthesis (FTS). In this work, KOH chemical activation was applied to modify N-doped carbon nanosheets supported Fe catalysts, which achieves support modification and promoter introduction simultaneously. The influence of KOH activation on pore structure, N configuration and residual K effect were discussed on Fe-based FTS catalyst. Upon KOH activation, the micro-porosity was enriched which improved the Fe dispersion. Meanwhile, the N configuration was regulated through KOH in-situ reacting with carbon matrix. Further investigation on residual K revealed a combined effect of K and N. The physical structure, electronic properties and phase compositions after activation were characterized by N 2 -physisorption, XRD, Raman, TEM, XPS and Mössbauer spectroscopy. Combing with the catalytic performance, we demonstrated that the pyrrolic N sites and suitable K residuals contribute to electron donation to Fe species, collectively promoting Fe carburization accompanied by higher C 2 –C 4 = productivity. This finding is expected to offer an activation method for preparation of N-doped carbon supported metal catalysts.