Molybdenum modified Montmonrillonite clay as an efficient catalyst for low temperature NH3‐SCR

BACKGROUND: Selective catalytic reduction of nitrogen oxides with ammonia (NH₃‐SCR) is an effective method for the nitrogen oxides (NOₓ) removal. This study aimed to develop a highly efficient NH₃‐SCR catalyst using the naturally available Montmonrillonite (Mt) clay as the catalyst support. RESULTS: Mt was processed into PILC by Al/Zr intercalations, impregnated with MnCe mixed active components and loaded with transition metals to achieve X‐AlZr‐PILC‐MnCe (X = V, W, Co or Mo) catalysts. The optimized Mo‐AlZr‐PILC‐MnCe showed the best NH₃‐SCR performance with a NO conversion rate of nearly 100% in the temperature range of 240–300 °C, and N₂ selectivity of above 85% in the range of 140–300 °C. CONCLUSIONS: The catalysts were characterized by SEM, BET, XRD, XPS, H₂‐TPR, NH₃‐TPD to define the relationships between structure, chemical properties and catalytic activity. The enhanced catalytic performance of Mo‐AlZr‐PILC‐MnCe was mainly owing to the increased acidity and better redox ability. In situ DRIFT studies indicated the deposition of Mo changed the reaction from the E‐R to the L‐H mechanism. © 2020 Society of Chemical Industry