Design of a Reactor Cell for Modulated Excitation Raman and Diffuse Reflectance Studies of Selective Catalytic Reduction Catalysts

Despite the large pool of spectroscopic studies about selective catalytic reduction (SCR), transient response experiments have not yet been fully utilized to extract key mechanistic and kinetic insights. Here, we describe the construction and performance characteristics of a spectroscopic cell that can be used for such an experimental design. The rapid gas exchange in the reaction chamber of the cell makes it amenable to modulated excitation (ME) experimentation. We show case studies wherein this cell was used for Raman, visible, and infrared spectroscopy under ME conditions to investigate the SCR mechanism over three of the most industrially relevant SCR catalysts today—V 2 O 5 /TiO 2 , Cu-SSZ-13, and Fe-ZSM-5.