In-containing BEA zeolite for selective catalytic reduction of NOx: Part I: Synthesis, characterization and catalytic activity

In this work we show the effect of preparation method of BEA zeolite, the indium loading method, on the performance for NOx-SCR with methane in presence of oxygen. Temperature programmed ammonium desorption (TPAD), XRD, BET, NMR-MAS of 27Al and Fourier transformed infrared spectroscopy (FTIR) of pyridine adsorbed on the samples, allowed us to correlate the catalytic activity with the nature of the active sites of the catalysts. The catalyst activity is affected by strong Brønsted sites and the type of In precursor (InCl3 and In2O3) and is influenced by the indium loading methods. The ion exchange in liquid phase method results in a higher activity than ion exchange in solid phase method.

Graphical abstractIn-HBEA prepared by ion exchange in liquid phase (IELP) using InCl3 (sample A) and In-HBEA prepared by ion exchange in solid phase (IESP) (sample B) are the most selective materials for the reduction of NO with methane; in this way methane is consumed selectively for the reduction of NO to N2 at 450–500 °C; this fact can be observed especially in the case of sample A. Figure optionsDownload full-size imageDownload as PowerPoint slide