Enhanced NiO Dispersion on a High Surface Area Pillared Heterostructure Covered by Niobium Leads to Optimal Behaviour in the Oxidative Dehydrogenation of Ethane

This is the peer reviewed version of the following article: E. Rodríguez-Castellón, D. Delgado, A. Dejoz, I. Vázquez, S. Agouram, J. A. Cecilia, B. Solsona, J. M. López Nieto, Chem. Eur. J. 2020, 26, 9371, which has been published in final form at https://doi.org/10.1002/chem.202000832. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.[EN] A Nb-containing siliceous porous clay heterostructure (PCH) with Nb contents from 0 to 30 wt %) was prepared from a bentonite and used as support in the preparation of supported NiO catalysts with NiO loading from 15 to 80 wt %. Supports and NiO-containing catalysts were characterised by several physicochemical techniques and tested in the oxidative dehydrogenation (ODH) of ethane. The characterisation studies on Nb-containing supports showed the presence of well-anchored Nb(5+)species without the formation of Nb(2)O(5)crystals. High dispersion of nickel oxide with low crystallinity was observed for the Nb-containing PCH supports. In addition, when NiO is supported on these Nb-containing porous clays, it is more effective in the ODH of ethane (ethylene selectivity of ca. 90 %) than NiO supported on the corresponding Nb-free siliceous PCH or on Nb2O5(ethylene selectivities of ca. 30 and 60 %, respectively). Factors such as the NiO-Nb(5+)interaction, the NiO particle size and the properties of surface Ni(n+)species were shown to determine the catalytic performance.The authors would like to acknowledge the Ministerio de Ciencia, Innovacion y Universidades of Spain (CRTl2018-099668-B-C21, RTl2018-099668-B-C22 and MAT2017-84118-C2-1-R projects). Authors from ITQ also thank Project SEV-2016-0683 for supporting this research. D.D. thanks MINECO and Severo Ochoa Excellence Program for his fellowship (SVP-2014-068669).Rodríguez-Castellón, E.; Delgado-Muñoz, D.; Dejoz, A.; Vázquez, I.; Agouram, S.; Cecilia, JA.; Solsona, B.... (2020). Enhanced NiO Dispersion on a High Surface Area Pillared Heterostructure Covered by Niobium Leads to Optimal Behaviour in the Oxidative Dehydrogenation of Ethane. Chemistry - A European Journal. 26(42):9371-9381. https://doi.org/10.1002/chem.202000832S937193812642L. Nichols Industry Perspectives: Global petrochemical sector to see robust growth to 2020 Hydrocarbon Processing 2017.Hermabessiere, L., Dehaut, A., Paul-Pont, I., Lacroix, C., Jezequel, R., Soudant, P., & Duflos, G. (2017). Occurrence and effects of plastic additives on marine environments and organisms: A review. Chemosphere, 182, 781-793. doi:10.1016/j.chemosphere.2017.05.096Jia, L., Evans, S., & Linden, S. van der. (2019). Motivating actions to mitigate plastic pollution. 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Ferric sludge derived from the process of water purification as an efficient catalyst and/or support for the removal of volatile organic compounds

[EN] Ferric chloride solutions are used as coagulants or flocculants in water treatment operations for human consumption. This treatment produces large amounts of clay-type solids formed mainly of montmorillonite with iron oxides and humic substances. This ferric sludge can be used as an efficient catalyst for the removal of volatile organic compounds (VOCs) by total oxidation. This waste isolated in the purification process has been activated by calcinations in air, characterized by several physicochemical techniques and employed as a catalyst for the removal by total oxidation of representative VOCs: toluene, propane and mixtures of toluene/propane with or without water. This ferric sludge has shown a catalytic activity one order of magnitude higher than that of a commercial iron oxide. This high activity has been related to the composition of the sludge (as it contains active metal oxides such as oxides of iron and manganese) and to the porous structure (leading to a reasonably high surface area). Moreover, it can be also used as a support for platinum, showing comparable (or even higher) catalytic activity than a similar platinum catalyst supported on conventional gamma-alumina.The authors would like to acknowledge the DGICYT in Spain CTQ2012-37925-C03-2, CTQ2015-68951-C3-1-R and CTQ2015-68951-C3-3-R. Authors from UV thank the University of Valencia (UV-INV-AE16-484416 project) and MINECO (MAT2017-84118-C2-1-R project) for funding. Finally, authors thank the Electron Microscopy Service of SCSIE of Universitat de Valencia for their support.Sanchis, R.; Dejoz, A.; Vázquez, I.; Vilarrasa-García, E.; Jiménez-Jiménez, J.; Rodríguez-Castellón, E.; López Nieto, JM.... (2019). Ferric sludge derived from the process of water purification as an efficient catalyst and/or support for the removal of volatile organic compounds. Chemosphere. 219:286-295. https://doi.org/10.1016/j.chemosphere.2018.12.002S28629521

Total Oxidation of Propane Using CeO2 and CuO-CeO2 Catalysts Prepared Using Templates of Different Nature

[EN] Several CeO2 and CuO-CeO2 catalysts were prepared using different methods, i.e., a homogeneous precipitation with urea, a nanocasting route using CMK-3 carbon as a hard template and a sol¿gel process using Poly(methyl methacrylate) (PMMA) polymer as a soft template, and tested in the total oxidation of propane. The catalysts were characterized by a number of physicochemical techniques (XRD, N2 adsorption, TPR, XPS, Raman spectroscopy) showing distinct characteristics. For each series, Cu-Ce-O catalysts with low Cu-loadings (5 wt % CuO) showed the highest activity, higher than those samples either without copper or with high Cu-loading (13 wt % CuO). The incorporation of copper leads to an increase of the concentration of bulk defects but if the Cu-loading is too high the surface area drastically falls. The highest activity in the total oxidation of propane was achieved by Cu-containing ceria catalysts synthesized using a polymer as a template, as this method yields high surface area materials. The surface area and the number of bulk/sub-surface defects of the ceria seem to be the main properties determining the catalytic activityThe authors would like to acknowledge the DGICYT in Spain CTQ2012-37925-C03-2, CTQ2015-68951-C3-1-R, CTQ2015-68951-C3-3-R. Authors from ITQ also thank Project SEV-2012-0267 for financial support. B.S, R.S and A.M.D also thank UV-INV-AE16-484416.Solsona, B.; Sanchis, R.; Dejoz, AM.; Garcia, T.; Ruiz-Rodríguez, L.; López Nieto, JM.; Cecilia, JA.... (2017). Total Oxidation of Propane Using CeO2 and CuO-CeO2 Catalysts Prepared Using Templates of Different Nature. Catalysts. 7(4):96-110. https://doi.org/10.3390/catal7040096S961107

Porous clays heterostructures as supports of iron oxide for environmental catalysis

[EN] Porous Clays Heterostructures (PCH) from natural pillared clays (bentonite with a high proportion of montmorillonite) have been used as supports of iron oxide for two reactions of environmental interest: i) the elimination of toluene (a representative compound of one of the most toxic subsets of volatile organic compounds, aromatics) by total oxidation and ii) the selective oxidation of H2S to elemental sulfur. For both reactions these catalysts have resulted to be remarkably more efficient than similar catalysts prepared using conventional silica as a support. Thus, in the total oxidation of toluene it has been observed that the catalytic activity obtained using siliceous PCH is two orders of magnitude higher than that with conventional silica. The catalytic activity has shown to be dependant of the capacity of the support for dispersing iron oxide in a way that the higher the dispersion of iron oxide on the surface of the support, the higher is the activity. In the case of the selective oxidation of H2S to S both higher catalytic activity and higher selectivity to S have been observed using siliceous porous clays heterostructures than using conventional silica. Highly dispersed FeOx species have been shown as highly selective towards elemental sulfur whereas more aggregated FeOx species favour the formation of sulphur oxides decreasing the selectivity to S. Analyses of the surface by XPS have shown the predominance of sulfate species in the catalysts presenting low selectivity to elemental sulfur.The authors would like to acknowledge the DGICYT in Spain (CTQ2015-68951-C3-1-R, CTQ2015-68951-C3-3-R, CTQ2012-37925-C03-2, CTQ2012-37925-C03-3 and CTQ2012-37984-C02-01) and FEDER for financial support. We also thank the University of Valencia for funding (UV-INV-AE-16-484416) and SCSIE-UV for assistance.Sanchis Martinez, R.; Cecilia, J.; Soriano Rodríguez, MD.; Vazquez, I.; Dejoz, A.; López Nieto, JM.; Rodriguez-Castellon, E.... (2008). Porous clays heterostructures as supports of iron oxide for environmental catalysis. Chemical Engineering Journal. 334:1159-1168. https://doi.org/10.1016/j.cej.2017.11.060S1159116833

Total oxidation of VOCs on mesoporous iron oxide catalysts: soft chemistry route versus hard template method

[EN] A comparative study on the total oxidation of volatile organic compounds, VOCs, on mesoporous iron oxide catalysts prepared by soft chemistry route versus those achieved by hard template methodThe authors would like to acknowledge the DGICYT in Spain (CTQ2012-37925-C03-1, CTQ2012-37925-C03-2, CTQ2012-37925-C03-3 and CTQ2012-37984-C02-01) and FEDER for financial support. We also thank the University of Valencia and SCSIE-UV for assistance.Solsona Espriu, BE.; Garcia, T.; Sanchis Martinez, R.; Soriano Rodríguez, MD.; Moreno, M.; Rodríguez-Castellon, E.; Agouram, S.... (2016). Total oxidation of VOCs on mesoporous iron oxide catalysts: soft chemistry route versus hard template method. The Chemical Engineering Journal and the Biochemical Engineering Journal. 290:273-281. https://doi.org/10.1016/j.cej.2015.12.109S27328129

Zr supported on non-acidic sepiolite for the efficient one-pot transformation of furfural into γ-valerolactone

10 figures y 4 tables.-- Supplementary information available.The growing demand of energy needs the search for alternative energy sources different to fossil fuels. The use of biomass as energy source is one of the most studied, because there are high value products that can be produced from biomass. One of these products is γ-valerolactone, that can be obtained from furfural, which is a biomass derived product. To transform furfural into γ-valerolactone is necessary a bifunctional catalyst and a hydrogen source. In this work, γ-valerolactone was obtained from furfural using 2-propanol as solvent and as hydrogen donor on Zr supported on sepiolite catalysts. It was demonstrated that sepiolite, which is a cheap material, can be used to develop efficient catalysts to produce high yields to γ-valerolactone from furfural in one-pot. The catalysts that presented the highest yield to γ-valerolactone were the ones with intermediate Zr-content (9–17 wt% ZrO2). The highest TOFs have been obtained by those catalysts with Zr-loading up to 9 wt% ZrO2, in which the ZrO2 nanoparticles are well dispersed on the support and no formation of large clusters of ZrO2 has been observed. Lewis and Brønsted acid sites are essential in the catalysts to produce the reactions to transform furfural into γ-valerolactone in one-pot, although in the present work, low concentration of Brønsted acid sites were observed in the catalysts. A possible positive role of basic sites to promote some intermediate steps has been also proposed. The catalytic results obtained are in the order of catalysts with Zr supported on zeolitic supports.A.G. thanks MINECO for the pre-doctoral grant (PRE2018-085211). This work was funded by the MAT2017-84118-C2-1-R, MAT2017-84118-C2-2-R, MCIN/AEI/10.13039/501100011033/projects and FEDER Una manera de hacer Europa. Authors thank the electron microscopy CAI center of UCM. Authors also thank the Generalitat Valenciana for CIAICO/2021/094.Peer reviewe

The selective oxidative dehydrogenation of ethane over hydrothermally synthesised MoVTeNb catalysts

Mo–V–Te–Nb metal oxide catalysts prepared by hydrothermal synthesis and heat-treated in N2 at high temperatures (600–700 °C) show high activity and selectivity for the oxidative dehydrogenation of ethane to ethene. Yields of ethene of 75% have been obtained at 400 °C on the best catalysts.Dejoz Garcia, Ana Maria, [email protected]