Zeolite-Vanadium Catalyst Blend for SCR Thermal Stability

The patent uses composite materials by combining transition metal exchanged zeolite with vanadium-based catalyst components. This composite structure allows the zeolite to provide high NOx reduction activity while the vanadium component contributes to thermal stability, preventing dealumination during hydrothermal ageing. The synergistic combination resolves the contradiction between activity and stability.

The patent converts the harmful effect of hydrocarbon adsorption into a beneficial feature by designing the catalyst to utilize hydrocarbons for in-situ generation of ammonia through reforming reactions. The hydrocarbons that would normally cause coking are instead transformed into useful reducing agents (ammonia) that enhance NOx reduction, particularly during cold start conditions. This resolves the contradiction by turning the harmful adsorption into a beneficial ammonia generation mechanism.

The patent merges vanadium-based SCR catalyst with transition metal exchanged zeolite components to create a hybrid catalyst system. The vanadium component provides thermal durability and resistance to hydrothermal ageing, while the zeolite component enhances NOx conversion efficiency and provides sulfur tolerance. This merging resolves the contradiction by combining the strengths of both catalyst types to achieve both thermal durability and high performance.

The patent employs composite materials by integrating aluminosilicate zeolite with vanadium-based catalyst components. The zeolite framework provides active sites for high NOx reduction rates, while the vanadium component stabilizes the structure against dealumination during hydrothermal ageing. This composite approach maintains both the high reactivity of the zeolite and the structural stability required for long-term durability.