N2O Catalytic Decomposition and NH3-SCR Coupling Reactions over Fe-SSZ-13 Catalyst: Mechanisms and Interactions Unraveling via Experiments and DFT Calculations

Simultaneous catalytic elimination of NO and N2O from exhausts is an ideal solution for nitric or adipic acid plants. Herein, Fe -based zeolite catalysts were applied for the NH3-NOx-N2O system. 1% Fe-SSZ-13 performed excellent catalytic activity with 100% conversions for both NOx and N2O at 400-600 degrees C. Experimental and computational research studies unraveled that NO could significantly improve N2O decomposition by reacting with alpha O* to generate easily desorbed NO2; furthermore, NO-alpha O* also can decrease charge density of Fe-alpha O*, facilitating alpha O* desorbed from the Fe sites. Besides, NH3 inhibits low-temperature deN2O activity due to strong competitive adsorption with N2O; however, NH3 accelerates N2O decomposition by consuming alpha O* and simultaneously reduces N2O as a reductant at high temperature. Interestingly, the alpha O* generated from N2O decomposition would enhance NO oxidation to NO2, which is beneficial to NH3-selective catalytic reduction. This work elaborates fundamental insights for simultaneous abatement of NOx and N2O and provides candidate catalyst for application.