Infrared and volumetric study of NO adsorption on Pd-H-ZSM-5

Nature of CO and NO Interactions with Pd-H-ZSM-5 Catalyst: A Comparative Study of DFT-Based Cluster and ONIOM Methods

“…Moreover, binding of CO and NO with Pd-H-ZSM-5 are much larger than the binding of PdCO and PdNO adducts with H-ZSM-5 (E ads values for PdCO-H-ZSM-5 are -6.52 kcal/mol in HZ7 and -10.04 kcal/mol in HZ93; E ads values for PdNO-H-ZSM-5 are -4.46 kcal/mol in HZ7 and -8.33 kcal/mol in HZ93). The strong Pd-CO and Pd-NO interactions probably result in carbonyl and nitrosyl complexes of Pd, which is also suggested by IR and FTIR studies [9,11]. Table 1 presents the calculated vibrational frequencies for carbonyl and nitrosyl adsorbed on Pd supported on H-ZSM-5.…”

“…These values agree well with the experimentally determined NO frequency of Pd ? -NO (1881 cm -1 ) and Pd-NO/H-ZSM-5 (1876 cm -1 ) [9]. There is a red shift in frequency of adsorbed NO in Pd-H-ZSM-5 complexes compared to that in free NO molecule (1991.1 cm -1 ).…”

“…Since the pioneering work of Li and Armor [5] on the catalytic activity of Co-ZSM-5, metal exchanged ZSM-5 have appeared to be promising catalysts for the catalytic reduction of NO x by methane in the presence of excess O 2 . Recently, zeolitesupported Pd catalysts; especially, Pd-ZSM-5 and Pd-H-ZSM-5 have drawn a lot of worldwide attention [6][7][8][9][10][11] due to their excellent catalytic activity in methane combustion [12][13][14], NO reduction by CH 4 [15] and many organic reactions [16]. The findings of Nishizaka and Misono [17] suggest that Brønsted acid sites may play an important role in stabilizing Pd in a highly dispersed state, and this form of Pd is required to achieve high activity and selectivity for NO reduction by CH 4 in the presence of O 2 .…”

Characterization of Pd-mordenite Catalysts for NO Decomposition

“…This is in accordance with the CO adsorption and hydrogen chemisorption measurements that demonstrated the higher metal dispersion of PdMOR-COM. All samples showed a band at 1876 cm -1 that has been previously observed on Pd/H-MOR and Pd/H-ZSM5 catalysts calcined in oxygen [14,15] that is assigned to NO molecules adsorbed onto oxidized Pd (Pd 2? ).…”

Effect of precursor acidity on zeolite supported Pd catalyst properties and hydrodeoxygenation activity for the production of biofuel

“…[24]reported a linear relationship between excessive thermal treatments and crystallinity (i.e. crystal growth) but an inverse correlation with catalytic activity.…”