Co3O4@PC derived from ZIF-67 as an efficient catalyst for the selective catalytic reduction of NOx with NH3 at low temperature

Herein, a series of Co3O4 nanoparticles inlaid in porous carbon (CoOx@PC-T) were successfully prepared via first pyrolysis of ZIF-67 in argon atmosphere at different temperature and then oxidized in 5% O-2/Ar mixed gas. The as-made samples were employed as catalysts for selective catalytic reduction of NOx with NH3 at low temperature (100 degrees C-200 degrees C). The effect of pyrolysis temperature on the microstructure, textural properties, and chemical properties of CoOx@PC-T were characterized by TG-MS, BET, XRD, SEM, TEM, H-2-TPR and XPS in detail. Results show that the pyrolysis temperature has a significant effect on the carbonization degree of carbon in ZIF-67, and which in turn affects the exposure and oxidization of cobalt nanoparticles on the catalyst surface. Experiments results show that CoOx@PC-800 display the highest NOx conversion ratio, which is attributed to its higher ratio of Co3+/Co2+ and large specific surface area. Moreover, the stability, H2O and SO2 resistance of CoOx@PC-800 were also studied.