Vanadium compounds are used extensively as catalysts; Vanadium pentoxide V₂O₅, is used as a catalyst in manufacturing sulfuric acid by the contact process In this process sulfur dioxide (SO
₂) is oxidized to the trioxide (SO
₃): In this redox reaction, sulfur is oxidized from +4 to +6, and vanadium is reduced from +5 to +4:
V₂O₅ + SO₂ → 2 VO₂ + SO₃
The catalyst is regenerated by oxidation with air:
4 VO₂ + O₂ → 2 V₂O₅
Similar oxidations are used in the production of maleic anhydride:
C₄H₁₀  + 3.5 O₂  →   C₄H₂O₃  +  4 H₂O
Phthalic anhydride and several other bulk organic compounds are produced similarly.
These green chemistry processes convert inexpensive feedstocks to highly functionalized, versatile intermediates.

Vanadium is an important component of mixed metal oxide catalysts used in the oxidation of propane and propylene to acrolein, acrylic acid or the ammoxidation of propylene to acrylonitrile.
In service, the oxidation state of vanadium changes dynamically and reversibly with the oxygen and the steam content of the reacting feed mixture.
Vanadium compounds are used extensively as catalysts; Vanadium pentoxide V₂O₅, is used as a catalyst in manufacturing sulfuric acid by the contact process In this process sulfur dioxide (SO
₂) is oxidized to the trioxide (SO
₃): In this redox reaction, sulfur is oxidized from +4 to +6, and vanadium is reduced from +5 to +4:
V₂O₅ + SO₂ → 2 VO₂ + SO₃
The catalyst is regenerated by oxidation with air:
4 VO₂ + O₂ → 2 V₂O₅
Similar oxidations are used in the production of maleic anhydride:
C₄H₁₀  + 3.5 O₂  →   C₄H₂O₃  +  4 H₂O
Phthalic anhydride and several other bulk organic compounds are produced similarly. These green chemistry processes convert inexpensive feedstocks to highly functionalized, versatile intermediates.
Vanadium is an important component of mixed metal oxide catalysts used in the oxidation of propane and propylene to acrolein, acrylic acid or the ammoxidation of propylene to acrylonitrile. In service, the oxidation state of vanadium changes dynamically and reversibly with the oxygen and the steam content of the reacting feed mixture.
Vanadium