Carbon ‐ Supported Transition Metal Sulfides

Abstract

Abstract First, second and third row transition metal sulfides ranging from group VI to group VIII c, supported on activated carbon were evaluated for their ability to catalyze the hydrodesulfurization of thiophene at atmospheric pressure. X‐ray photoelectron spectroscopy was used to measure the chemical state and to obtain an indication of the dispersion of the supported sulfide particles. Second and third row elements display volcano curves with catalytic activity varying over more than an order of magnitude and maxima occuring at Rh in the second and Ir in the third row. First row elements show a twin‐shaped pattern with maximum activity located at Cr and Co. The resemblance of these experimental activity trends with those previously reported for unsupported transition metal sulfides demonstrate the advantage of carbon supports in studies on the intrinsic catalytic properties of small sulfide particles. A correlation between the catalytic activity of second and third row elements and the shift in XPS binding energies between metal and metal sulfide phases was found. Superior catalysts have low binding energy shifts and preserve a high degree of metal character under sulfiding conditions.