DFT-ONIOM study of Au/ZSM-5 catalyst: Active sites, thermodynamic and vibrational frequencies

Effect of Charge on the Catalytic Activity of CO Oxidation by zeolite Supported Single Site Palladium: A Density Functional Study

“…The CO molecule adsorbs in a liner configuration on the zeolite supported Pd atom with Pd‐C−O bond angles of 179.2°, 178.6° and 177.3°, respectively, in the neutral and charged clusters. The geometries of these structures are similar to those of CO adsorbed on Pd−H‐ZSM‐5 and Au‐ZSM‐5 complexes . Our calculations indicate favorable binding of CO in all the oxidation states.…”

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

“…Therefore, NO can be displaced by CO from the adsorption site in Pd-H-ZSM-5. This observation is similar to that in Au-ZSM-5 complexes [21]. The very much comparable results in Table 1 for the geometry, energetics as well as for vibrational analysis confirm that the small 7T cluster would provide cost-effective model for studying adsorption and reaction on Pd-H-ZSM-5 system.…”

“…The CO molecule gets adsorbed on the Pd atom in H-ZSM-5 framework in a linear configuration with Pd-C-O angles of 179.2°and 178.3°, respectively, in PdHZ7 and PdHZ93 clusters. The geometries of these structures are similar to those of CO adsorbed Au-ZSM-5 complexes[21] and Pt-H-Mordenite complexes[22]. Values of Pd-C bond lengths in the two clusters are found to be 1.85 and 1.86 Å , respectively.…”

“…Quantum chemical investigations have been widely and successfully applied to study the properties of metal particles within zeolites [18][19][20][21][22][23]. Harmsen et al [24] reported a model description of the interaction of a Pd atom with a zeolite Brønsted acid site.…”

Nitrogen oxides and SO2 adsorption on Au/MOR catalyst: Adsorption sites, thermodynamic and vibrational frequencies. ONIOM study

“…The H ads , G ads and Au NO distances are very similar for Au/T1 and Au/T4, as well as the angle Au N O (∠ Au N O ) and the NO stretching frequency NO . The NO values calculated herein, 1851 and 1841 cm −1 , are in agreement with the experimental values of 1820 and 1900 cm −1 reported by Ichikawa and coworkers [35] for NO adsorption on Au/ZSM-5 and, the H ads values are in agreement with the values reported for NO adsorption on the Au/ZSM-5, H ads = −23 kcal/mol [56]. To test the influence of the atomic basis sets on the E ads H ads and G ads values, calculations with full-electron 6-31+G(d,p) basis Tables 3 and 4, the LANL2DZ basis set will be used to describe and analyze the nitrogen oxides and SO 2 adsorption phenomenon on the Au/MOR catalyst in this work.…”