Ring opening of decalin and methylcyclohexane over alumina-based monofunctional WO3/Al2O3 and Ir/Al2O3 catalysts

► Monofunctional acid (WO3/Al2O3) and metal (Ir/Al2O3) as catalysts. ► Reactions: decalin and methylcyclohexane (MCH) selective ring opening. ► For WO3/Al2O3 catalysts, ring contraction (RC) precedes ring opening (RO). ► For Ir/Al2O3 catalysts, only direct ring opening was observed. ► Similar evolution of RO selectivity with MCH and decalin conversion was observed.