Transient CO Oxidation as a Versatile Technique to Investigate Cu2+ Titration, Speciation and Sites Hydrolysis on Cu–CHA Catalysts: The Cu Loading Effect

Abstract The investigation of the ZCu 2+ (OH) − and Z 2 Cu ions modifications during NH 3 -SCR on Cu–CHA catalysts is a key aspect to clarify still-debated low-T redox SCR mechanism. In previous works, dry transient CO oxidation protocol has been employed identify generation dinuclear structures under conditions representative SCR–RHC: solvation promotes inter-cage mobility coupling , acting as catalytic centers for process, while results inactive. Herein same protocol, with pre-stored applied set variable loading (0.7–2.4% w/w) but fixed Si/Al: an increasing content produced net positive effect production, coherent growing population, further enhancement was observed in presence H O. analysis integral production enabled predict maximum conversion, corresponding titration whole each catalyst condition, verifying initial Conversely, water, evaluated asymptotic total contents. This finding permits generalize recent study where combined TRMs, DFT FTIR were used probe complete reversible sites hydrolysis pairing O thus activating participation species, too. These also highlight versatility effectiveness multi-purpose technique catalysts.