Mesoporous Zeolite Y-Supported Co Nanoparticles as Efficient Fischer–Tropsch Catalysts for Selective Synthesis of Diesel Fuel

Abstract

Cobalt nanoparticles were loaded onto mesoporous zeolite Na–Y (Na–meso-Y) by melt infiltration and impregnation methods. As compared to impregnation, melt infiltration resulted in Co nanoparticles with a narrower size distribution. The Co/Na–meso-Y catalyst prepared by the melt infiltration exhibited higher C10–C20 (diesel fuel) selectivity. The hydrogenolysis of heavier hydrocarbons was confirmed to occur under Fischer–Tropsch reaction conditions. Our studies for the hydrogenolysis of n-hexadecane revealed that the catalyst by the melt infiltration was more active and selective for the formation of C10–C15 hydrocarbons. We propose that the narrower Co size distribution favors the selective hydrogenolysis and thus the C10–C20 selectivity in Fischer–Tropsch synthesis. The addition of Mn with a proper content could further improve the diesel fuel selectivity to 65% by suppressing the formations of CH4 and lighter hydrocarbons. The Mn-modified Co/Na–meso-Y catalyst was very stable and no deactivation was obs...