Mechanism of Propane Adsorption and the Following NO_x Reduction over an In/BEA Catalyst: A Computational Study

Abstract

To expand the knowledge on hydrocarbon selective catalytic reduction (SCR) and follow the research steps of methane-SCR and propane-SCR in our previous work, we studied the characteristics of propane adsorption on In/BEA zeolite, explored the NO and NO2 activation process on a propane adsorbed catalyst, and calculated the reaction enthalpy of two reaction pathways. Results showed that O site in the L-model (the [InO]+/BEA structure) was the main active site in the adsorption process, and any of the carbon atoms in the propane molecule could react with it, with a lower adsorption energy than methane (−3.20 vs −2.98 eV). Also, NO or NO2 could not be directly activated on the propane adsorbed catalyst, indicating that the process may be complicated. In addition, propane reduces the NO or NO2 molecule with two different pathways and the final products were less stable than those of methane (−5.6 vs −20 eV). These results could explain the fact that propane and methane had different reaction temperatures and would further deepen our understanding of the propane-SCR process.

H/D Exchange of n-Butane on In-Modified Zeolite BEA Investigated by 1H Magic-Angle Spinning Nuclear Magnetic Resonance In Situ

“…2−4 Zeolites modified by indium have been applied as catalysts for alkane aromatization, 5,6 alkylation of simple aromatics, 7 dehydrogenation of alkanes, 8−10 or selective catalytic reduction of NO x by hydrocarbons. 11 However, detailed systematic studies of the role of indium in alkane activation mechanisms are lacking.…”

“…Further improvements of zeolite catalytic properties are brought by the introduction of various metals into zeolite pores, providing the additional function of the catalyst (dehydrogenation/hydrogenation activity, red/ox properties, etc. ). − Zeolites modified by indium have been applied as catalysts for alkane aromatization, , alkylation of simple aromatics, dehydrogenation of alkanes, − or selective catalytic reduction of NO x by hydrocarbons . However, detailed systematic studies of the role of indium in alkane activation mechanisms are lacking.…”