Density functional theory (DFT) studies of vanadium-titanium based selective catalytic reduction (SCR) catalysts

Area of Science:

• Surface Chemistry
• Catalysis
• Computational Chemistry

Background:

• Selective Catalytic Reduction (SCR) is crucial for NOx abatement.
• Vanadium-titanium based catalysts are widely used in SCR denitrification.
• Understanding surface reaction mechanisms is key to catalyst optimization.

Purpose of the Study:

• To summarize surface chemical reactions on vanadium-titanium SCR catalysts.
• To evaluate the suitability of different structural models for DFT calculations.
• To elucidate the SCR reaction mechanism and identify key intermediates.

Main Methods:

• Density Functional Theory (DFT) calculations.
• Comparison of non-periodic and periodic structural models for catalyst surfaces.
• Analysis of reaction pathways and intermediates in the SCR process.

Main Results:

• Periodic structural models provide more accurate representations of catalyst surfaces compared to non-periodic models.
• The Eley-Rideal mechanism is proposed for the SCR reaction between NH3 and NO.
• NH2NO is identified as a significant intermediate with multiple formation pathways.

Conclusions:

• Periodic DFT calculations are essential for reliable modeling of SCR catalyst surfaces.
• The proposed Eley-Rideal mechanism and NH2NO intermediate offer insights into SCR catalysis.
• Further studies should consider the impact of H2O, SO2, and metal promoters on SCR catalyst performance.