0 2 except for ni ac a catalyst at 600 and 700 u00b0 c 4 9 for all catalysts benzene yield decreased as the reaction temperature increased from 600 to 800 u00b0 c the decrease in benzene yield was probably because high temperature promoted the decomposition of benzene into permanent gases benzene is more thermally stable than toluene and its decomposition requires more energy in summary with respect to the current embodiment nickel nitrate was found to be a good nickel precursor for preparing char supported nickel catalyst the catalytic efficiency of toluene removal for the three catalysts was ranked from highest to lowest as ni ac u2014 n gt ni ac ah gt ni ac a nickel particle size of the catalyst impregnated with nickel nitrate ni ac u2014 n was smaller than that of catalyst impregnated with nickel acetate ni ac a and ni ac ah the particle size of catalyst impregnated with nickel acetate decreased with hydrazine reduction but was still larger than catalyst impregnated with nickel nitrate the primary gas product of steam reforming of toluene was h 2 followed by co and co 2 the h 2 content and co 2 decreased as the temperature increased from 600 to 700 u00b0 c while the co content increased with decrease in temperature with respect to toluene and naphthalene steam reforming in this embodiment when temperature was below 900 u00b0 c the conversions of toluene and naphthalene were similar at 900 u00b0 c the conversion of toluene was significantly higher than that of naphthalene increase in temperature significantly increased reforming efficiencies of both toluene and naphthalene the toluene conversion increased from 36 to 99 and naphthalene conversion increased from 37 to 92 as temperature increased from 700 to 900 u00b0 c the conversion.