Bismuth-modified vanadyl pyrophosphate catalysts

• Published in: Catalysis letters Vol. 89; no. 1-2; pp. 87 - 93
• Main Authors: TAUFIQ-YAP, Y. H, TAN, K. P, WAUGH, K. C, HUSSEIN, M. Z, RAMLI, I, ABDUL RAHMAN, M. B
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01.07.2003; Springer Nature B.V
• Subjects: Alkenes; Anhydrides; Bismuth; Catalysis; Catalysts; Catalysts: preparations and properties; Chemistry; Exact sciences and technology; General and physical chemistry; Isobutanol; Maleic anhydride; Oxidation; Oxygen; Refluxing; Selectivity; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Valence; maleic anhydride; Heterogeneous catalysis; butane oxidation; Transition metal Compounds; vanadyl pyrophosphate; Bismuth; Modified catalyst; promoter; Vanadyl Diphosphates
• ISSN: 1011-372X; 1572-879X
• DOI: 10.1023/A:1024775611157

A 1 bismuth-doped VPO catalyst was prepared by refluxing Bi(NO3)3 and VOPO4 ⋅ 2H2O in isobutanol. The incorporation of Bi into the VPO lattice lowered the overall V oxidation state from 4.24 to 4.08. It also lowered both the peak maximum temperature for the desorption of oxygen from the lattice from 1001K (undoped) to 964K with a shoulder at 912K and the peak maxima for H2 temperature-programed reduction from 863, 1011 and 1143K (undoped) to 798, 906 and 1151K. The total oxygen desorbed from the Bi-doped catalyst was only one-fourth that of the undoped catalyst, while the amount of oxygen removed by TPR was roughly the same for both catalysts. These results suggest that in anaerobic oxidation, the Bi-doped catalyst will have roughly the same activity as in undoped catalyst in C4 hydrocarbon oxidation but will have a higher selectivity to products such as olefins and maleic anhydride.