Co3O4/HZSM-5 catalysts for methane combustion: The effect of preparation methodologies.

A series of Co 3 O 4 /HZSM-5 catalysts with different Co 3 O 4 loadings were prepared by incipient wetness impregnation followed by thermal calcination or dielectric barrier discharge (DBD) plasma decomposition. Their catalytic performances for the complete combustion of methane were evaluated from 300 to 700 °C. The plasma decomposed samples exhibit much higher catalytic activity than the calcined ones. Among all the samples tested, the plasma decomposed catalyst with 20 wt.% loading of Co 3 O 4 possesses the highest catalytic activity with T 10 (10% CH 4 conversion) at 300 °C and T 100 (complete conversion) at 550 °C. The excellent catalytic activity of the DBD plasma decomposed samples would attribute to well-dispersed Co 3 O 4 , enhanced low-temperature reducibility, high content of lattice oxygen and adsorbed oxygen species, as well as the low formation tendency of the intermediate of Co-formate. [ABSTRACT FROM AUTHOR]