Design of active NiCo2O4‐δ spinel catalyst for abatement of CO‐CH4 emissions from CNG fueled vehicles

Trivedi, Suverna; Прасад, Рам; Gautam, Shivam

doi:10.1002/aic.16162

Cited by 24 publications

(10 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The relatively low binding energy of the signal associated with the presence of Ni 2+ cations in a spinel lattice (855.3 eV) also denoted that these species were mainly a part of the NiCo2O4 spinel instead of the NiAl2O4, for which the binding energy of that signal would be expectedly higher (ca. 856.0 eV), as shown by other studies [36,37]. As for the Co/Al sample the two features with the lowest binding energies, located at 779.5 and 781.0 eV, were assigned to Co 3+ and Co 2+ ions, respectively, while the signal centered at 783.2 eV was attributed to the presence of CoO in the surface of the samples [32,33].…”

Section: Physico-chemical Characterizationsupporting

confidence: 73%

“…The relatively low binding energy of the signal associated with the presence of Ni 2+ cations in a spinel lattice (855.3 eV) also denoted that these species were mainly a part of the NiCo 2 O 4 spinel instead of the NiAl 2 O 4 , for which the binding energy of that signal would be expectedly higher (ca. 856.0 eV), as shown by other studies [36,37]. The deconvolution and integration of the XPS spectra allowed for a quantitative analysis of the composition of the surface, as shown in Table 2.…”

Section: Physico-chemical Characterizationmentioning

confidence: 53%

See 1 more Smart Citation

Comparative Study of Strategies for Enhancing the Performance of Co3O4/Al2O3 Catalysts for Lean Methane Combustion

et al. 2020

View full text Add to dashboard Cite

Spinel-type cobalt oxide is a highly active catalyst for oxidation reactions owing to its remarkable redox properties, although it generally exhibits poor mechanical, textural and structural properties. Supporting this material on a porous alumina can significantly improve these characteristics. However, the strong cobalt–alumina interaction leads to the formation of inactive cobalt aluminate, which limits the activity of the resulting catalysts. In this work, three different strategies for enhancing the performance of alumina-supported catalysts are examined: (i) surface protection of the alumina with magnesia prior to the deposition of the cobalt precursor, with the objective of minimizing the cobalt–alumina interaction; (ii) coprecipitation of cobalt along with nickel, with the aim of improving the redox properties of the deposited cobalt and (iii) surface protection of alumina with ceria, to provide both a barrier effect, minimizing the cobalt–alumina interaction, and a redox promoting effect on the deposited cobalt. Among the examined strategies, the addition of ceria (20 wt % Ce) prior to the deposition of cobalt resulted in being highly efficient. This sample was characterized by a notable abundance of both Co3+ and oxygen lattice species, derived from the partial inhibition of cobalt aluminate formation and the insertion of Ce4+ cations into the spinel lattice.

show abstract

Section: Physico-chemical Characterizationsupporting

confidence: 73%

“…The relatively low binding energy of the signal associated with the presence of Ni 2+ cations in a spinel lattice (855.3 eV) also denoted that these species were mainly a part of the NiCo 2 O 4 spinel instead of the NiAl 2 O 4 , for which the binding energy of that signal would be expectedly higher (ca. 856.0 eV), as shown by other studies [36,37]. The deconvolution and integration of the XPS spectra allowed for a quantitative analysis of the composition of the surface, as shown in Table 2.…”

Section: Physico-chemical Characterizationmentioning

confidence: 53%

Comparative Study of Strategies for Enhancing the Performance of Co3O4/Al2O3 Catalysts for Lean Methane Combustion

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Trivedi et al developed NiCo 2 O 4−δ spinel catalysts by reactive calcination of precursors in a CO‐air environment to expose more active sites. The catalysts achieved 98% methane conversion at 422 °C (GHSV = 12 000 mL g −1 h −1 ) . Tao et al investigated the mechanism of complete methane oxidation on NiCo 2 O 4 via in situ studies and theoretical simulations .…”

Section: Introductionmentioning

confidence: 99%

Bowtie‐Shaped NiCo₂O₄ Catalysts for Low‐Temperature Methane Combustion

Dai

Kumar

Zhu

et al. 2019

Adv Funct Materials

View full text Add to dashboard Cite

Bowtie-shaped NiCo 2 O 4 nanostructures are prepared using a hydrothermal method. Variation of the synthesis parameters, including reaction time, additives, and calcination temperature, allows an understanding of the origin of the bowtie-shaped structure to be developed. Methane oxidation experiments performed using temperature-programed oxidation (TPO) show that the new materials, which do not contain precious metals, have excellent activity for low-temperature methane combustion, with 100% conversion at ≈410 °C (gas hourly space velocity (GHSV): 90 000 mL (STP) g −1 h −1 ). The structure-activity relationships of the bowtie-shaped nanostructures are explored. The relatively low exhaust temperature in NGVs means that the activation of methane, which has the strongest CH bond of any hydrocarbon, is challenging from a chemical perspective. It is not surprising that the quest for effective lowtemperature methane oxidation catalysts has focused mainly on systems involving precious metals, such as platinum and palladium. [11][12][13][14][15] Metal oxidesupported PdO catalysts are generally considered to represent the state of the art for methane combustion catalysts. [16][17][18][19][20] Recent research in this field has focused on improving activity at low temperatures, [21,22] reducing the required loading of metal [23,24] and improving the thermal and hydrothermal stability of PdO catalysts. [25][26][27][28][29][30] Exciting recent advances include the development of core-shell Pd@CeO 2 catalysts with high activity and thermal stability, demonstrating complete conversion to CO 2 below 400 °C (gas hourly space velocity (GHSV) = 200 000 mL g −1 h −1 ). [21] Pd@ZrO 2 /Si-Al 2 O 3 catalysts that are stable in the presence of high concentrations of water vapor have also been proposed recently. [25] NiO@PdO/Al 2 O 3 catalysts that show good activity and stability with only 0.2 wt% Pd loading have been prepared [23] as well as Pd-based bimetallic nanocrystalline catalysts, in which the promotional effects of different transition metals have been examined. [26] Although Pd-based catalysts show excellent activity, the high price and low abundance of palladium are limiting factors to practical application, [31] and both the hydrothermal stability and SO 2 tolerance for these catalysts need to be improved. For this reason, the development of alternative catalysts based on non-noble metals is attractive. [32] These include single metal oxide-based catalysts (CuO, [33] Co 3 O 4 , [34] and MnO 2 [35] ), perovskite, [36,37] spinel, [38,39] and hexaaluminate [40] catalysts. Among these, Co 3 O 4 exhibits good activity for methane combustion attributed to a spinel-type structure with variable Co oxidation states and a high density of oxygen vacancies on the surface. [41] Additionally, the specific exposed facets and morphology of Co 3 O 4 plays an important role in the catalysis. [42,43] Materials with exposed (110) planes show enhanced catalytic activity for methane oxidation compared with those only exposing (100) or (111) face...

show abstract

“…Herein, the calcination process involves the thermal decomposition of the basic carbonate precursor (obtained after precipitation step) to form active oxide species seem to play a significant role in the catalyst preparation. In general, the calcination conditions such as gas atmosphere, rate of heating, calcination temperature, and gas flow rate (GHSV) can considerably alter the physicochemical characteristics of a catalyst and in turn, affect its catalytic activity 5–8 …”

Section: Introductionmentioning

confidence: 99%

“…In general, the calcination conditions such as gas atmosphere, rate of heating, calcination temperature, and gas flow rate (GHSV) can considerably alter the physicochemical characteristics of a catalyst and in turn, affect its catalytic activity. [5][6][7][8] During the calcination step, agglomeration or sintering of the basic carbonates, oxide, and intermediate species might take place, causing an unfavorable decrease in active specific surface area and increase in crystallite size. 9 Therefore, various strategies have been used over the years to reduce sintering during the calcination step.…”

Section: Introductionmentioning

confidence: 99%

Influence of calcination atmospheres on the physicochemical properties and catalytic activity of Ni₁Co₁O_x catalyst for CO oxidation

Neha

Прасад

Singh

2021

Asia-Pacific J Chem Eng

Self Cite

View full text Add to dashboard Cite

Nano‐Ni1Co1Ox spinel catalysts were prepared via a coprecipitation method, followed by calcination in different atmospheres (air, CO air, N2, and static air flow) tested CO oxidation in air. The calcination of basic cobalt‐nickel precursor in CO air mixture flow (4.5 vol.%) led to the formation of nano‐Ni1Co1Ox spinel with highest specific surface area, smallest crystallite size, porous, and well‐dispersed oxygen deficient structural defect morphology as revealed by N2 physiosorption, X‐ray diffraction (XRD), Fourier transform infrared (FT‐IR), and scanning electron microscopy–energy dispersive X‐ray analysis (SEM–EDX) results. The calcination in air and N2 flow improved the CO oxidation activity compared to calcination in static air. Though, the greatest activity was achieved with CO air calcined catalyst giving complete CO oxidation at 150°C.

show abstract

Design of active NiCo₂O_4‐δ spinel catalyst for abatement of CO‐CH₄ emissions from CNG fueled vehicles

Cited by 24 publications

References 42 publications

Comparative Study of Strategies for Enhancing the Performance of Co3O4/Al2O3 Catalysts for Lean Methane Combustion

Comparative Study of Strategies for Enhancing the Performance of Co3O4/Al2O3 Catalysts for Lean Methane Combustion

Bowtie‐Shaped NiCo₂O₄ Catalysts for Low‐Temperature Methane Combustion

Influence of calcination atmospheres on the physicochemical properties and catalytic activity of Ni₁Co₁O_x catalyst for CO oxidation

Contact Info

Product

Resources

About

Design of active NiCo2O4‐δ spinel catalyst for abatement of CO‐CH4 emissions from CNG fueled vehicles

Cited by 24 publications

References 42 publications

Comparative Study of Strategies for Enhancing the Performance of Co3O4/Al2O3 Catalysts for Lean Methane Combustion

Comparative Study of Strategies for Enhancing the Performance of Co3O4/Al2O3 Catalysts for Lean Methane Combustion

Bowtie‐Shaped NiCo2O4 Catalysts for Low‐Temperature Methane Combustion

Influence of calcination atmospheres on the physicochemical properties and catalytic activity of Ni1Co1Ox catalyst for CO oxidation

Contact Info

Product

Resources

About

Design of active NiCo₂O_4‐δ spinel catalyst for abatement of CO‐CH₄ emissions from CNG fueled vehicles

Bowtie‐Shaped NiCo₂O₄ Catalysts for Low‐Temperature Methane Combustion

Influence of calcination atmospheres on the physicochemical properties and catalytic activity of Ni₁Co₁O_x catalyst for CO oxidation