Industrial & Engineering Chemistry Research, Vol.53, No.40, 15600-15610, 2014
Supported Nickel-Cobalt Bimetallic Catalysts Derived from Layered Double Hydroxide Precursors for Selective Hydrogenation of Pyrolysis Gasoline
Generation of bimetallic sites on supported catalysts has been proved to be capable of enhancing catalytic performance when compared to those of the corresponding monometallic ones. Herein we report the preparation of novel Al2O3-supported NiCo bimetallic catalysts (NiCo/Al2O3) derived from Ni2+Co2+Al3+-containing layered double hydroxides (NiCoAl-LDHs) precursors, which were in situ grown on the surface and in the pore canals of microspherical gamma-Al2O3, and their catalytic performance for selective hydrogenation of pyrolysis gasoline. Bimetallic NiCo/Al2O3 derived from LDHs precursor exhibited the better catalytic performance than the sample prepared by impregnation. The appropriate amounts of substitution of nickel for cobalt improved the catalytic activity and stability dramatically, indicating the synergistic effects of nickel and cobalt in terms of the hydrogenation reactivity. The enhanced reducibility and smaller particles for NiCo/Al2O3 samples derived from LDHs precursor were proposed to suppress the coke formation during the hydrogenation reaction, leading to improve catalytic activity and stability.