A Collective Case Screening of the Zeolites made in Japan for High Performance NH3-SCR of NOx

Zeolites demonstrating better SCR of NOx performance due to wide temperature activity, hydrothermal stability and N2 selectivity have been identified under a joint research initiative by the Research Association of Automotive Internal Combustion Engines (AICE), Japan. Based on the AICE’s standards, over 25 zeolites with different structures and pore dimensions were investigated and their SCR efficiency and durability have been compared. While the performances of the top contenders cannot be related to a single parameter, the results suggest that the SAR, Cu quality/quantity, pore dimensions, diffusivity and acidity play a combined role in deciding the SCR activity and selectivity.