Effect of treatment method on the performance of boron nitride supported iron catalysts in the Fischer-Tropsch synthesis

Three boron nitride (BN) supported iron catalysts were prepared by the incipient-wetness impregnation method and characterized by XRD, TEM, FT-IR, and H₂-TPR; their phase structure, morphology, reduction behavior and performance in the F-T synthesis were investigated. The results indicate that the addition of Cu promoter has little influence on the phase structure of BN support, whereas the addition of sodium borate can improve the crystallinity of BN support. Although the change in the catalyst morphology by introducing Cu and sodium borate is very small, the addition of Cu and sodium borate can decrease the reduction temperature of the BN-supported iron-based catalysts. For F-T synthesis under 340℃, 2 MPa, GHSV=1500 h^-1 and n(H₂)/n(CO)=2, the conversions of CO over Fe/BN, Fe/BNM and Fe-Cu/BN are 12.3%, 36.2% and 31.6%, respectively and the corresponding selectivities to CH₄ are 57.9%, 26.8% and 44.7%, respectively. Fe-Cu/BN and Fe/BNM exhibit higher activity than Fe/BN, suggesting that adding promoter and improving the interaction between support and active component can both enhance the activity of boron nitride supported iron catalysts in F-T synthesis, which may give a clue to the design of highly active BN-supported iron catalysts.