Preparation of biomorphic porous La_0.8Ce_0.2Fe_0.3Co_0.7O₃ perovskite‐type catalysts for automobile exhaust purification

Abstract

Biomorphic porous La0.8Ce0.2Fe0.3Co0.7O3 perovskite‐type catalysts are synthesized through a facile bio‐templating method taking wood fiber as template for achieving the four‐way purification of PM, NOx, CO, and HC emitted by automobile exhausts. The catalyst samples were characterized by X‐ray diffractometer, Fourier‐transform infrared spectroscopy, scanning electron microscope and Brunauer–Emmett–Teller analysis. The results showed that catalyst sample calcined at 700°C obtained high purity, high surface area (4.01 m2/g), wide pore size distribution and retained the initial wood fiber structure, which was suitable for purifying automobile exhausts. In addition, the performances for four‐way purification under the simulated exhaust were analyzed by simulation test bench. The highest purification efficiency of PM, NOx, HC, and CO can reach 92%, 92%, 98%, and 76%, separately. Moreover, four‐way purification mechanism was deduced according to the theoretical research of Mars‐van krevelen on the redox reaction mechanism and experimental result.