Investigation of Different Apatites-Supported Co3O4 as Catalysts for N2O Decomposition

Two types of apatite supports including hydroxyapatite (HAP) and fluorapatite (FAP) were prepared by the co-precipitation method. Supported Co catalysts with the above carriers were synthesized from Co(NO3)(2)center dot 6H(2)O via the impregnation method. The catalytic activity for N2O decomposition was investigated using a continuous flowing microreactor system. The catalytic results demonstrated that the Co/HAP exhibited more excellent catalytic activity as well as the impurity gas (H2O, O-2, and NO) resistance capability than the Co/FAP in the temperature range of 300-600 degrees C. Furthermore, the physicochemical properties of Co/HAP and Co/FAP were determined by several relevant characterization methods. The obtained experimental results revealed that Co/HAP possessed larger specific surface area, more ion-exchanged Co2+ and stronger oxygen desorption capacity than Co/FAP, which are the key factors for high N2O decomposition activity. Moreover, compared with Co/FAP, Co/HAP has not only more basic content, but also higher basic site density, which may be also conducive to enhance the electron donating ability of Co2+, thereby promoting the N2O catalytic decomposition. [GRAPHICS]

Automated summary

The study showed that Co/HAP exhibited better catalytic activity for N2O decomposition compared to Co/FAP, due to its larger specific surface area, more ion-exchanged Co2+, and stronger oxygen desorption capacity. Additionally, Co/HAP had higher basic content and basic site density than Co/FAP, which may enhance the electron donating ability of Co2+ and promote the N2O catalytic decomposition.