Investigation of NO2 and NO interaction with an Fe-ZSM-5 catalyst by transient response methods and chemical trapping techniques

Ruggeri, Maria Pia; Selleri, Tommaso; Colombo, Massimo; Nova, Isabella; Tronconi, Enrico

doi:10.1016/j.jcat.2015.02.003

Cited by 44 publications

(57 citation statements)

References 41 publications

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“…On the Ce-Zr-based hybrids, there is no N 2 O formation whatsoever while the hybrids with degraded hopcalite (Fig. 2c) [10,11] and NH 2 NO, which has been postulated in theoretical studies [15,16]. However, given the strong dependence of the synergistic effect on the distance between the components [5], radical species as discussed e.g.…”

Section: Discussionmentioning

confidence: 72%

“…Instead, unstable intermediates seem to leave the surface of one component and find active sites on the other one, which convert them to the final product. This motive is reminiscent of a reaction mechanism for standard SCR recently derived by E. Troncini's group from trapping experiments, in which nitrite adsorbates formed in the interaction of NO + O 2 with Fe-ZSM-5 were trapped by admixed BaO/Al 2 O 3 [10,11].…”

Section: Discussionmentioning

confidence: 87%

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Hybrid catalysts for the selective catalytic reduction (SCR) of NO by NH 3 . On the role of fast SCR in the reaction network

Salazar

Hoffmann

Singer

et al. 2016

Applied Catalysis B: Environmental

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Section: Discussionmentioning

confidence: 72%

Section: Discussionmentioning

confidence: 87%

Hybrid catalysts for the selective catalytic reduction (SCR) of NO by NH 3 . On the role of fast SCR in the reaction network

Salazar

Hoffmann

Singer

et al. 2016

Applied Catalysis B: Environmental

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“…After the influx of NO+O2 for 5 minutes, new vibration peak signals began to appear at 1260 cm -1 and 1600 cm -1 increasingly, which indicated NH3 was totally consumed. Furthermore, the vibration peak at 1260 cm -1 could be regarded as nitrate species, while the peak at 1600 cm -1 could be attributed to nitrite and adsorbed NO2 (Ruggeri et al, 2014(Ruggeri et al, , 2015. It was obvious that at the moment adsorbed NH3 species was consumed completely, NO would be rapidly oxidized on the surface of the CoCeOx catalyst.…”

Section: Accepted Manuscriptmentioning

confidence: 99%

Simultaneous Catalytic Removal of VOCs and NOx with the Dual-layered Catalyst of CoCeOx and V2O5/TiO2

Zhang

et al. 2021

Aerosol Air Qual. Res.

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NO and volatile organic compounds (VOCs) are ones of exhaust with high irritation and toxicity, thus it is very necessary to develop a catalyst that can simultaneously remove them. In this study, a type of dual-layered catalyst has been prepared by combining CoCeOx and V2O5/TiO2 as different functional layers. The dual-layered catalyst was tested under NO, NH3, propane and the mixing atmosphere, achieving great NOx removal efficiency and good propane degradation under wide range temperature window. It is presented that NO conversion could reach 100% at 225 °C and kept more than 80% at 175-300 °C, while VOCs degradation reached 80% above 260 °C. Moreover, the dual-layered catalyst with different construction is surveyed to reveal the mechanism included in this special construction. It is supposed that V2O5/TiO2 layer possesses rich acid sites which adsorbs NH3 as an ammonia buffer part and CoCeOx layer provides good oxidizing ability to oxidize NO and propane. The combination moderates the competitive adsorption between NH3 and propane which is the initial obstacle for multiple pollutants removal.

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“…Therefore, the nitrocompounds and the adsorbed NO 2 observed in the FTIR studies (Figure 8) are generated from the reactions. Ruggeri et al [38] described how the reaction between nitrites and NO 2 to give nitrates, and NO constitutes an equilibrium (6). Hence, during the NO elimination studies in the catalysts with Pd, the reaction expressed in (6) does not take place until the catalysts are left in an air atmosphere, and the NO concentration decreases.…”

Section: Influence Of the Presence Of Water On The Catalyst Surface On The Oxidation Mechanismmentioning

confidence: 99%

Influence of Water on the Oxidation of NO on Pd/TiO2 Photocatalysts

et al. 2020

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Two series of new photocatalysts were synthesized based on modification with Pd of the commercial P25 photocatalyst (EVONIK®). Two techniques were employed to incorporate Pd nanoparticles on the P25 surface: photodeposition (series Pd-P) and impregnation (series Pd-I). Both series were characterized in depth using a variety of instrumental techniques: BET, DRS, XRD, XPS, TEM, FTIR and FESEM. The modified series exhibited a significant change in pore size distribution, but no differences compared to the original P25 with respect to crystalline phase ratio or particle size were observed. The Pd0 oxidation state was predominant in the Pd-P series, while the presence of the Pd2+ oxidation state was additionally observed in the Pd-I series. The photoactivity tests were performed in a continuous photoreactor with the photocatalysts deposited, by dip-coating, on borosilicate glass plates. A total of 500 ppb of NO was used as input flow at a volumetric flow rate of 1.2 L·min−1, and different relative humidities from 0 to 65% were tested. The results obtained show that under UV-vis or Vis radiation, the presence of Pd nanoparticles favors NO removal independently of the Pd incorporation method employed and independently of the tested relative humidity conditions. This improvement seems to be related to the different interaction of the water with the surface of the photocatalysts in the presence or absence of Pd. It was found in the catalyst without Pd that disproportionation of NO2 is favored through its reaction with water, with faster surface saturation. In contrast, in the catalysts with Pd, disproportionation took place through nitro-chelates and adsorbed NO2 formed from the photocatalytic oxidation of the NO. This different mechanism explains the greater efficiency in NOx removal in the catalysts with Pd. Comparing the two series of catalysts with Pd, Pd-P and Pd-I, greater activity of the Pd-P series was observed under both UV-vis and Vis radiation. It was shown that the Pd0 oxidation state is responsible for this greater activity as the Pd-I series improves its activity in successive cycles due to a reduction in Pd2+ species during the photoactivity tests.

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Investigation of NO2 and NO interaction with an Fe-ZSM-5 catalyst by transient response methods and chemical trapping techniques

Cited by 44 publications

References 41 publications

Hybrid catalysts for the selective catalytic reduction (SCR) of NO by NH 3 . On the role of fast SCR in the reaction network

Hybrid catalysts for the selective catalytic reduction (SCR) of NO by NH 3 . On the role of fast SCR in the reaction network

Simultaneous Catalytic Removal of VOCs and NOx with the Dual-layered Catalyst of CoCeOx and V2O5/TiO2

Influence of Water on the Oxidation of NO on Pd/TiO2 Photocatalysts

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