Abstract:
In consideration of the inferior performance of ZIF-67 derived Co
3O
4 catalyst in the low-temperature formaldehyde oxidation, manganese was utilized to modify Co
3O
4 catalyst. The results showed that the Mn-Co
3O
4 catalyst exhibited the superior HCHO oxidation activity and achieved 90% HCHO conversion at a WHSV of 60000 mL/(g
cat·h) and inlet HCHO concentration of 98.16 mg/m
3 at 118 ℃. XRD, Raman and BET results demonstrated that the Mn-Co
3O
4 catalyst possessed lower crystallinity, more defects and specific surface area, which was conducive to the adsorption of reactants and exposure of more active sites. XPS, H
2-TPR and O
2-TPD results indicated that the strong interaction between Mn and Co species prominently improved the low temperature reducibility and O
2 activation performance of Mn-Co
3O
4 catalyst, which endowed it with more abundant Co
3+ and surface-adsorbed oxygen species. Therefore, the Mn-Co
3O
4 catalyst exhibited superior HCHO oxidation performance. Based on
in-situ DRIFTS results, dioxymethylene and formate species were recognized as the main reaction intermediates of HCHO oxidation over the Mn-Co
3O
4 catalyst.