Mo−Fe Catalysts Supported on Activated Carbon for Synthesis of Liquid Fuels by the Fischer−Tropsch Process: Effect of Mo Addition on Reducibility, Activity, and Hydrocarbon Selectivity

Abstract

The effects of Mo loading (0−12 wt %) on the properties of activated-carbon- (AC-) supported Fe−Cu−K catalysts and their performance for Fischer−Tropsch synthesis are studied. Physicochemical properties studied include particle size, reducibility, and dispersion, and catalytic properties include activity, selectivity, and stability. Catalysts were characterized by N2 adsorption, energy-dispersive spectroscopy, X-ray diffraction (XRD), H2 temperature-programmed reduction (TPR), and CO chemisorption. Catalyst performance was studied at 310−320 °C, 2.2 MPa, 3 Nl/g-cat/h, and H2/CO = 0.9. Reaction results in a fixed-bed reactor show that addition of 6% Mo into the Fe−Cu−K/AC catalyst improves catalyst stability without sacrificing activity, but activity is suppressed dramatically on a 12% Mo-loaded catalyst. Detectable hydrocarbons of C1 to C34 are produced on the Fe−Cu−K/AC catalysts with or without Mo. However, the addition of Mo results in the production of more CH4 and less C5+ hydrocarbons. The Mo promot...