Periodic Operation of Three-Way Catalysts: From Synthetic Gas Bench Testing to Real-World Engine Performance

This study utilized a synthetic gas test bench (SGB) and two engine test benches (ETBs) to evaluate the periodic operation of an industrially relevant three-way catalyst formulation. The goal was to bridge the gap between laboratory-scale testing and real-world applications, ensuring the reliability of catalysts in engine environments under periodic conditions. SGB testing showed significant increases in NO, CO, and hydrocarbon conversion and N₂ selectivity under dynamic operation compared to stoichiometric steady-state conditions. Despite differences in ETB testing due to the realistic conditions, notable improvements in pollutant conversion were achieved. Challenges included inaccurate control of the mean air-fuel equivalence ratio (AFR) by the engine control unit and the AFR sensor. The findings underscore the importance of harmonizing engine operation with formulation-governed catalyst properties to minimize tailpipe emissions. Periodic operation emerges as a promising technique for enhancing catalyst efficiency in varying engine conditions.