Surfactant-aided hydrothermal preparation of La 2- xSr xCuO 4 single crystallites and their catalytic performance on methane combustion

Abstract

Perovskite-like oxide La 2- x Sr x CuO 4 ( x = 0, 1) single crystallites with microrod-like morphologies and tetragonal crystal structures were prepared hydrothermally at 240°C with poly(ethylene glycol) (PEG) or hexadecyltrimethyl ammonium bromide (CTAB) as a surfactant and after calcination at 850°C. The physicochemical properties of the materials were characterized by means of XRD, BET, SEM, TEM/SAED (selected-area electron diffraction), XPS and H 2-TPR techniques. It is found that doping Sr 2+ to La 2CuO 4 lattice enhanced the catalytic activity for methane combustion and the LaSrCuO 4 catalyst derived from PEG is the best among the tested ones. It is concluded that factors, such as adsorbed oxygen species concentration, reducibility and surface area, determined the catalytic performance of such single-crystalline materials.