Enhancing catalytic performance of phosphorus-modified ceria supported VPO catalysts for n-butane oxidation

• VPO/CeO2 and VPO/P-CeO2 catalysts have been firstly synthesized for selective oxidation of n-butane.
• The nature of the support has a great influence on the structure and property of VPO.
• VPO/P-CeO2 showed higher catalytic performance than bulk VPO and VPO/CeO2.

Vanadium phosphorus oxide (VPO) catalysts supported on CeO2 and P-modified CeO2 (P-CeO2) have been firstly synthesized for selective oxidation of n-butane to maleic anhydride (MA). The catalysts supported on P-CeO2 showed higher catalytic performance, especially higher MA selectivity than catalysts on pure ceria, and their specific activities (normalized to per unit mass of VPO loading) were also superior to that of bulk VPO. TG, TEM, XRD, Raman, H2-TPR and XPS results revealed that the structure and property of VPO are largely affected by the support. The loaded VPO existed almost wholly as VOPO4 phases on pure ceria, while mainly in the form of (VO)2P2O7 with small amount of VOPO4 phases on phosphorus-modified ceria. Both VPO/P-CeO2 and bulk VPO catalysts have the similar VPO phase structure, but the former showed the enhanced reducibility of V4+ phase. These differences in structure and properties of the catalysts were discussed and related to their different catalytic performances.

For the supported catalysts, NH4H2PO4-treatment can change the properties of the supports and thus affect the phase structure of the catalysts and change the catalytic performance.Figure optionsDownload high-quality image (194 K)Download as PowerPoint slide