Mechanism‐based kinetic modeling of standard NH 3 ‐ SCR over Cu‐ SSZ ‐13 catalysts using experimentally determined parameters

Abstract

Abstract Cu‐SSZ‐13 is a key catalyst for NH 3 ‐SCR in mobile aftertreatment systems, yet reliable kinetic modeling remains challenging due to the complex interplay among Cu speciation, NH 3 solvation, and oxidation side reactions. In this work, NO oxidation, NH 3 oxidation, and standard SCR over Cu‐SSZ‐13 catalysts with varying Cu loadings were systematically investigated, and a mechanism‐informed kinetic model was developed using experimentally derived kinetic parameters. The results show that NO oxidation and NH 3 oxidation are primarily associated with multinuclear Cu species, whereas standard SCR mainly proceeds on exchanged Cu ions through Cu II /Cu I redox cycling. Both NH 3 oxidation and standard SCR exhibit distinct low‐ and high‐temperature kinetic regimes associated with NH 3 ‐solvated mobile Cu species and framework‐bound immobile Cu species, respectively. The model successfully reproduces experimental reaction behavior across various Cu loadings and temperatures, demonstrating the effectiveness of experimentally constrained kinetic modeling for SCR reactor simulation and aftertreatment system optimization.