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

Graphical abstract Highlights • A series of CoO x @PC-T derived from ZIF-67are successfully prepared. • The carbonization of ZIF-67 is related to the pyrolysis temperature. • The carbonization degree affects the exposure and oxidization of cobalt particles. • CoO x @PC-800 shows the highest de-NO x performance. Abstract Herein, a series of Co 3 O 4 nanoparticles inlaid in porous carbon (CoO x @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 NO x with NH 3 at low temperature (100 °C–200 °C). The effect of pyrolysis temperature on the microstructure, textural properties, and chemical properties of CoO x @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 CoO x @PC-800 display the highest NO x conversion ratio, which is attributed to its higher ratio of Co3+/Co2+ and large specific surface area. Moreover, the stability, H 2 O and SO 2 resistance of CoO x @PC-800 were also studied. [ABSTRACT FROM AUTHOR]