Hydrocracking of Tar Components from Hot Coke Oven Gas over a Ni/Ce-ZrO2/γ-Al2O3 Catalyst at Atmospheric Pressure

Ni/Ce-ZrO2/γ-Al2O3 catalysts with different Ce-ZrO2 contents and Ni loadings were prepared by a two step impregnation method and characterized by X-ray diffraction, transmission electron microscopy, N2 adsorption, and temperature-programmed reduction. The catalysts were used for the hydrocracking of toluene and naphthalene, which were model tar compounds in hot coke oven gas, under atmospheric pressure at 800 °C. They showed excellent catalytic activity, stability, and some sulfur tolerance. Both toluene and naphthalene was converted into light fuel gases even at a low mole ratio of steam to carbon (S/C = 0.44). During the testing period of 7 h, no coke deposition was observed on the surface of the catalysts. The results indicated that the addition of Ce-ZrO2 limited the sintering of Ni particles and enhanced the catalytic activity. The Ni/Ce-ZrO2/γ-Al2O3 catalyst is promising for the direct removal of tar compounds in hot coke oven gas with low S/C ratios.