Structural transformation of vanadate nanotubes into vanadate oxides nanostructures during the dry reforming of methane

Oton, Lais F.; Coelho, Davi C.; Oliveira, Alcinéia C.; Araújo, Júlio; Lang, Rossano; Rodríguez‐Castellón, Enrique; Lucrédio, Alessandra Fonseca; Assaf, Elisabete Moreira; Reyna-Alvarado, Jorge; López‐Galán, Oscar A.; Ramos, Manuel

doi:10.1016/j.mcat.2019.110641

Cited by 7 publications

(4 citation statements)

References 60 publications

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“…Eventually, all the available PtOx nanoparticles on Nb2O5 surface act catalyzing the reaction along with the high conversions at higher temperatures. This is probably due to either the adsorption of CO by Pt sites and NOx decomposition, in line with the literature reports for SCR reactions [14,34].…”

Section: Temperature Effectssupporting

confidence: 90%

“…However, there is significantly more deactivation of the PtMo/Nb 2 O 5 and NiMo/Nb 2 O 5 catalysts by repeating the cycles of cutting in and cutting off again upon using the poisons during the CO-SCR reaction. Especially for PtMo/Nb 2 O 5 and NiMo/Nb 2 O 5 , the NO x conversion drops continuously for 24 h. Possible reasons for the activity decay could be due to the covering of a part of the Ni and Pt species by coke deposits from CO decomposition, as previously shown for Ni and Pt-based catalysts[34,51]. Although the NO x conversion decreases in the presence of SO 2 over CoMo/Nb 2 O 5 , the solid shows excellent tolerance to the poisons, when H 2 O is added simultaneously with sulfur during more than 20 h of reaction.…”

mentioning

confidence: 62%

“…A peak overlapping with the peak at 74.7 eV along with two peaks at 76.1 and 77.4 eV can be found for Pt 4f 5/2 (Figure 6b). According to the findings, the BE at 73.0 and 74.7 eV are due to Pt 2+ from PtO x species, whereas the contribution at 74.7 and 77.4 eV are assigned to the presence of Pt 4+ species [33,34]. The minor contribution at 71.4 eV is associated with the Pt • [33], although this specie is not probable in the fresh catalyst.…”

Section: Surface Acidity and Oxidation Statesmentioning

confidence: 89%

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Selective Catalytic Reduction of NOx by CO over Doubly Promoted MeMo/Nb2O5 Catalysts (Me = Pt, Ni, or Co)

et al. 2020

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Doubly promoted MeMo/Nb2O5 catalysts, in which Me = Pt, Ni, or Co oxides were prepared for the selective catalytic reduction of NOx by CO reaction (CO-SCR). Comparable chemical, textural, and structural analyses revealed similarities between NiMo and CoMo impregnated on Nb2O5, in contrast to PtMo sites, which were not homogeneously dispersed on the support surface. Both the acid function and metal dispersion gave a synergistic effect for CO-SCR at moderate temperatures. The reactivity of PtMo catalysts towards NOx and CO chemisorption was at low reaction temperatures, whereas the NOx conversion over CoMo was greatly improved at relatively high temperatures. Careful XPS, NH3-TPD, and HRTEM analyses confirmed that the large amounts of strong and moderate acid sites from PtOx entrapped on MoO3 sites induced high NOx conversions. NiMo/Nb2O5 showed poor performance in all conditions. Poisoning of the MeMo sites with water vapor or SO2 (or both) provoked the decline of the NOx conversions over NiMo and PtMo sites, whereas the structure of CoMo ones remained very active with a maximum NOx conversion of 70% at 350 °C for 24 h of reaction. This was due to the interaction of the Co3+/Co2+ and Mo6+ actives sites and the weak strength Lewis acid Nb5+ ones, as well.

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Section: Temperature Effectssupporting

confidence: 90%

mentioning

confidence: 62%

Section: Surface Acidity and Oxidation Statesmentioning

confidence: 89%

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Selective Catalytic Reduction of NOx by CO over Doubly Promoted MeMo/Nb2O5 Catalysts (Me = Pt, Ni, or Co)

et al. 2020

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“…The BE at 856.0 eV is within the range of values reported in the literature for Ni 2+ ions coming from NiAl 2 O 4 structure. 39,40 Moreover, the contribution for Ni 2p 3/2 is observable at 854.1 eV, which corresponds to Ni 2+ in NiO. These values in addition to that of Ni 2+ coming from NiAl 2 O 4 are expected, since the spent solid is greatly oxidized from the reactant gases of the TRM reaction.…”

Section: Morphology Composition Andmentioning

confidence: 90%

Investigation of the Deactivation Behavior of MeMo/La₂O₃-Al₂O₃- and MeMo/Nb₂O₅ Supported Catalysts (Me = Pt, Ni, and Co) in Tri-Reforming of Methane

et al. 2023

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The deactivation behaviors of MeMo/La2O3-Al2O3- and MeMo/Nb2O5 supported catalysts were investigated in the tri-reforming of methane (TRM). Characterizations by XRD, SEM-EDS, HRTEM, XPS, FTIR, and Raman spectroscopies were performed, after testing the catalysts in distinct TRM reaction conditions. The effects the transition metal components had on the causes of the deactivations of the solids were evaluated. The reaction conditions favored PtO x species residing in close contact with Mo sites to form a PtMo alloy. This enhanced the CH4 activation avoiding carbon accumulation in PtMo/Nb2O5. In contrast, LaPtO x [Pto]n surface oxygen species formation neither avoided sintering of the Pto particles on Mo/La2O3-Al2O3 nor oxidized the deposited carbon. The incorporation of Co in Mo/La2O-Al2O3 and Mo/Nb2O5 caused the continuous reoxidation of Co species because of the presence of O2, CO2, and steam reactants during the TRM reaction. Significant coke depositions on the Nio sites of NiMo/La2O3-Al2O3 and NiMo/Nb2O5 by the contribution of Boudouard and methane cracking reactions were observed, in short-term stability runs.

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High-performance self-doped V4+-V2O5 ion storage films grown in situ using a novel hydrothermal-assisted sol-gel composite method

Liu

Liang

Jiang³

et al. 2022

Electrochimica Acta

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Structural transformation of vanadate nanotubes into vanadate oxides nanostructures during the dry reforming of methane

Cited by 7 publications

References 60 publications

Selective Catalytic Reduction of NOx by CO over Doubly Promoted MeMo/Nb2O5 Catalysts (Me = Pt, Ni, or Co)

Selective Catalytic Reduction of NOx by CO over Doubly Promoted MeMo/Nb2O5 Catalysts (Me = Pt, Ni, or Co)

Investigation of the Deactivation Behavior of MeMo/La₂O₃-Al₂O₃- and MeMo/Nb₂O₅ Supported Catalysts (Me = Pt, Ni, and Co) in Tri-Reforming of Methane

High-performance self-doped V4+-V2O5 ion storage films grown in situ using a novel hydrothermal-assisted sol-gel composite method

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Structural transformation of vanadate nanotubes into vanadate oxides nanostructures during the dry reforming of methane

Cited by 7 publications

References 60 publications

Selective Catalytic Reduction of NOx by CO over Doubly Promoted MeMo/Nb2O5 Catalysts (Me = Pt, Ni, or Co)

Selective Catalytic Reduction of NOx by CO over Doubly Promoted MeMo/Nb2O5 Catalysts (Me = Pt, Ni, or Co)

Investigation of the Deactivation Behavior of MeMo/La2O3-Al2O3- and MeMo/Nb2O5 Supported Catalysts (Me = Pt, Ni, and Co) in Tri-Reforming of Methane

High-performance self-doped V4+-V2O5 ion storage films grown in situ using a novel hydrothermal-assisted sol-gel composite method

Contact Info

Product

Resources

About

Investigation of the Deactivation Behavior of MeMo/La₂O₃-Al₂O₃- and MeMo/Nb₂O₅ Supported Catalysts (Me = Pt, Ni, and Co) in Tri-Reforming of Methane