Oxidative dehydrogenation of ethane with oxygen catalyzed by K–Y zeolite supported first-row transition metals Original Research Article

Fe, Co, Ni, and Cu oxide loaded K–Y zeolites were synthesized using a two-step method, in which transition metals in the zeolite framework reacted with the anions in solution to form an insoluble salt which, when calcined, is expected to form an oxide that is anchored to the inner and/or outer zeolite surface(s). The catalytic properties of these zeolites, for the oxidative dehydrogenation of ethane (ODHE) to ethylene were then investigated. An ethylene selectivity of close to 80%, at an ethane conversion of >20% was achieved on a nickel oxide loaded K–Y catalyst. This is a higher ethylene selectivity, at higher ethane conversion, than was achieved using a previously reported Ni/KY catalyst. The effects of both reaction temperature and the O2/C2H6 ratio on the catalytic performance were examined. The apparent energy of activation for the ODHE reaction on the nickel oxide loaded K–Y catalyst was 51.5 ± 0.7 kJ/mol. The C2H4 selectivity at zero conversion (S0) on nickel oxide loaded K–Y was estimated for various O2/C2H6 ratios at a number of temperatures. The implications for the reaction mechanism of the S0 values, with regard to the relative values of critical rate constants are discussed.