Product distributions from the catalytic cracking of tetralin on HY at 400-degrees-C are not significantly influenced by the addition of oxygenated compounds with structures typical of those found in coal-derived liquids. Under cracking conditions, oxygen present in ether linkages is more resistant to removal than if present in phenolic structures. The presence of oxygenated species can suppress catalytic conversion of the feedstock, and lead to the formation of coke deposits which are resistant to removal on combustion at 500-degrees-C.