Porous LaFeO perovskite catalysts synthesized by different methods and their high activities for CO oxidation.

In this study, spherical α-FeO prepared by the hydrothermal method was used as a template for the first time; LaFeO perovskite catalysts were successfully synthesized by the molten salt method (M-LF-), sol-gel method (S-LF-), and co-precipitation method (C-LF-), respectively. To determine the optimal synthesis method, X-ray diffraction patterns were obtained and showed that single phase LaFeO with good crystallinity was prepared by the molten salt method after calcination at 600 °C for 4 h. SEM and TEM images showed that the M-LF-600 catalyst preserved the spherical structure of α-FeO template. Compared with the catalysts synthesized by the sol-gel method and co-precipitation method, the M-LF-600 catalyst had the highest BET surface area of 16.73 m g. X-ray photoelectron spectroscopy analysis showed that the M-LF-600 catalyst had the highest surface Fe/Fe molar ratio and the best surface oxygen adsorption capacity. The CO oxidation of the LaFeO catalyst demonstrated that the M-LF-600 catalyst had the best catalytic performance.