Selective Catalytic Steam Cracking (SCSC) is an interesting alternative for heavy oil upgrading which aims to use steam as source of hydrogen to crack the feedstock at relatively milder conditions (temperatures in the range of 400-500 degrees C) than steam reforming. This targets the formation of lighter liquid products over gas and coke. In this work, anthracene was used as model compound representing polyaromatic structures present in high molecular weight asphaltenes. The SCSC of anthracene was studied in the temperature range of 400-500 degrees C using a nickel based catalyst doped with Na, Ca or K and supported onto mesoporous Al2O3 in a micro-bomb reactor. The extent of anthracene SCSC depends on the nickel crystal size. However, high conversions values are detrimental to the selectivity to liquid products, since most of the intermediate products are further converted to the gas phase. (C) 2013 Elsevier B.V. All rights reserved.