Highly efficient simultaneous conversion of NOx and N2O using NH3 over Fe-beta zeolites: The critical role of preparation method

• Fe-beta catalysts were evaluated for simultaneous removal of NOx and N 2 O. • The N 2 O impact on DeNOx activity depends critically on the Fe loading method. • Liquid-state ion exchange induces a promotional effect on NOx conversion. • Incipient wetness and solid-state ion exchange lead to N 2 O-induced NOx inhibition. • Performance is governed by isolated Fe species and the Fe 2+ /(Fe 3+ +Fe 2+ ) ratio.