The catalytic performances and characterization of the catalysts La1.6Sr0.4CuO3.852, La1.6Sr0.4CuO3.857F0.143, and La1.6Sr0.4 CuO3.856Cl0.126 have been investigated for the oxidative dehydrogenation of ethane (ODE) to ethene. X-ray diffraction results indicated that the three catalysts have a single-phase tetragonal K2NiF4-type structure. The incorporation of fluoride or chloride ions in the La1.6Sr0.4CuO4-δ lattice can significantly enhance C2H6 conversion and C2H4 selectivity. We observed 83.2% C2H6 conversion, 76.7% C2H4 selectivity, and 63.8% C2H4 yield over La1.6Sr0.4CuO3.857F0.143 and 79.6% C2H6 conversion, 74.6% C2H4 selectivity, and 59.4% C2H4 yield over La1.6Sr0.4CuO3.856Cl0.126 under the reaction conditions of C2H6/O2/N2 molar ratio 2/1/3.7, temperature 660°C, and space velocity 6000 mlh-1 g-1. With the rise in space velocity, C2H6 conversion decreased, whereas C2H4 selectivity increased. Life studies showed that the two catalysis were durable within 60 h of on-stream ODE reaction. Based on the results of X-ray photoelectron spectroscopy, O2 temperature-programmed desorption, and C2H6 and C2H6/O2/N2 (2/1/37 molar ratio) pulse studies, we conclude that (i) the inclusion of halide ions in the La1.6Sr0.4CuO4-δ lattice could promote lattice oxygen mobility, and (ii) the O- species accommodated in oxygen vacancies and desorbed below 600°C favor ethane complete oxidation whereas the lattice oxygen species desorbed in the 600-700°C range are active for ethane selective oxidation to ethene. By regulating the oxygen vacancy density and Cu3+/Cu ratio in the K2NiF4-tyDe halo-oxide catalyst, one can generate a durable catalyst with good performance for the ODE reaction.
Scopus Subject Areas
- CH generation
- Ethane oxidative dehydrogenation
- KNiF-type halo-oxide catalyst
- LaSrCuOX (X = F, Cl)
- ODE reaction