Exhaust gas purification catalyst suppressing influence of iron compound

摘要

An exhaust gas purification catalyst contains titanium oxide as a main component and an oxide of one element or two or more elements selected from the group consisting of tungsten (W), molybdenum (Mo), and vanadium (V) as an active component, wherein the exhaust gas purification catalyst contains phosphoric acid or a water soluble phosphoric acid compound so that the atomic ratio of phosphorus (P) to a catalytically active component represented by the following formula is more than 0 and 1.0 or less; P/catalytically active component (atomic ratio)=number of moles of P/(number of moles of W+number of moles of Mo+number of moles of V).

主权项

1. A method for purifying an exhaust gas, comprising:
contacting the exhaust gas with an exhaust gas purification catalyst; wherein the exhaust gas purification catalyst comprises titanium oxide as a main component and an oxide of one element or two or more elements selected from the group consisting of tungsten (W), molybdenum (Mo), and vanadium (V) as an active component; wherein the active component is reacted with a phosphoric acid or a water soluble phosphoric acid compound to form a complex thereof so that the atomic ratio of phosphorus (P) to a catalytically active component represented by the following formula is 0.2 to 1.0; P/catalytically active component (Atomic ratio)=number of moles of P/(number of moles of W+number of moles of Mo+number of moles of V); wherein the exhaust gas contains nitrogen oxide and elemental mercury; and wherein the nitrogen oxide is reduced by ammonia.