CuO modified vanadium-based SCR catalysts for Hg⁰ oxidation and NO reduction

Area of Science:

• Environmental Catalysis
• Materials Science
• Chemical Engineering

Background:

• Mercury (Hg ⁰) emissions pose significant environmental risks.
• Vanadium-based catalysts are crucial for selective catalytic reduction (SCR) of NOx.
• Effective oxidation of elemental mercury is essential for its removal from industrial emissions.

Purpose of the Study:

• To investigate the impact of copper oxide (CuO) modification on vanadium-titanium (VWTi) SCR catalysts for Hg ⁰ oxidation.
• To correlate catalyst properties with Hg ⁰ oxidation performance.
• To explore the influence of flue gas components on the catalytic process.

Main Methods:

• Catalyst preparation via impregnation.
• Characterization of catalyst properties (e.g., redox, dispersion).
• Evaluation of catalytic performance for Hg ⁰ oxidation and NO removal under varying conditions.

Main Results:

• The 7% Cu/VWTi catalyst demonstrated superior Hg ⁰ oxidation and NO removal efficiency within the 280-360°C range.
• Enhanced redox properties and well-dispersed CuO species contributed to improved catalytic activity.
• CuO existed as a monolayer on the 7% Cu/VWTi catalyst, maximizing performance.
• Oxygen (O ₂), nitrogen oxides (NO), sulfur dioxide (SO ₂), and hydrogen chloride (HCl) promoted Hg ⁰ oxidation, while ammonia (NH ₃) inhibited it.

Conclusions:

• Copper modification significantly enhances the Hg ⁰ oxidation capability of VWTi SCR catalysts.
• Monolayer dispersion of CuO is key to achieving high catalytic performance.
• Strategic placement of the catalyst downstream of the SCR reactor can mitigate ammonia inhibition.
• The study provides insights into the mechanism of Hg ⁰ oxidation over Cu/VWTi catalysts.