Catalysis Today, Vol.153, No.3-4, 143-149, 2010
Hydrothermal synthesis and catalytic performance of single-crystalline La2-xSrxCuO4 for methane oxidation
The microsized perovskite-like oxide La2-xSrxCuO4 (x = 0, 1) single crystallites with a rod-like morphology were fabricated with KOH as the alkaline source at a hydrothermal temperature of 180-260 degrees C and after calcination at 850 degrees C. and characterized by means of the XRD, BET, SEM, SAED (selected area election drill action). O-2-TPD, and H-2-TPR techniques. The catalytic performance of the materials was evaluated for methane combustion It is shown that (i) the single-crystalline cuprate catalyst outperformed its poly-crystalline counterpart (ii) the doping of Sr2+ to the La2CuO4 lattice enhanced the catalytic activity, (iii) the LaSrCuO4 catalyst fabricated with 12 mol/L KOH as the alkaline source at a hydrothermal temperature of 260 degrees C showed the best performance (the temperature for 90% CH4 conversion = 667 degrees C) for methane combustion at CH4/O-2 molar ratio = 1/10 and SV = 50,000 mL/(g h), and (iv) there was a clear relationship between the alpha-oxygen desorption or reducibility and catalytic activity It is concluded that the more adsorbed oxygen species, better reducibility, single crystallinity, and unique morphology are responsible for the excellent performance of the LaSrCuO4 single crystallite in catalyzing the combustion of methane. (C) 2010 Elsevier B.V. All rights reserved
Keywords:Perovskite-like oxide catalyst;Single-crystalline strontium-substituted;lanthanum cuprate;Hydrothermal synthesis;Microrod-like morphology;Methane combustion