000087002 001__ 87002
000087002 005__ 20200716101534.0
000087002 0247_ $$2doi$$a10.1039/c9cy01490j
000087002 0248_ $$2sideral$$a115363
000087002 037__ $$aART-2019-115363
000087002 041__ $$aeng
000087002 100__ $$0(orcid)0000-0003-3211-0485$$aJulián, Ignacio
000087002 245__ $$aPolyoxometalates as alternative Mo precursors for methane dehydroaromatization on Mo/zsm-5 and Mo/mcm-22 catalysts
000087002 260__ $$c2019
000087002 5060_ $$aAccess copy available to the general public$$fUnrestricted
000087002 5203_ $$aThe conversion of methane into higher molecular weight hydrocarbons of greater added value has emerged as one of the grand challenges of the 21st century. The non-oxidative methane dehydroaromatization (hereafter MDA) reaction is a promising methane valorisation reaction since it transforms methane into added-value aromatics and olefins, namely benzene, naphthalene and ethylene. Molybdenum-promoted ZSM-5 zeolite has proven to be one of the most effective catalysts for MDA providing a shape-selective environment for the conversion of methane into benzene. However, one of the principle disadvantages of using aluminosilicates in the presence of methane is that the catalyst suffers from rapid deactivation induced by coke formation, which ultimately leads to a decrease in activity and aromatics selectivity, making the process unsuitable for large-scale industrial applications. Better control of the metal dispersion on the surface of the aluminosilicate supports represents a crucial factor to partially suppress catalyst coking and improve stability. Here we show how different molecular polyoxomolybdate (POM) anions can be used as alternative Mo precursors to conventional Mo salts for the preparation of catalysts for the MDA reaction. Molecular dynamics simulations and experimental testing were conducted to characterize the interphase interactions between polyoxomolybdates and zeolite surfaces at the atomistic level and to evaluate the MDA performance of different POM-based catalysts supported on ZSM-5 and MCM-22, respectively. The catalysts prepared using hexamolybdate anions, [Mo6O19]2-, were found to be more active and selective towards benzene than those employing the commercial heptamolybdate, [Mo7O24]6-. The Mo loading and dispersion of MoOx species were found to be the key factors leading to enhanced catalytic stability on ZSM-5 and MCM-22-based supports for MDA where the 5% Mo6/MCM-22 catalyst provided a constant aromatics yield above 7% for more than 18 hours time-on stream operating at 700 °C with a diluted methane flow under atmospheric pressure. The zeolitic catalysts prepared with the Mo6 precursor were found to be amongst the most promising MDA catalysts in the literature and the results of this study pave the way for the selection and use of different POMs as innovative metal precursors to formulate new catalysts and further improve the MDA reaction process.
000087002 536__ $$9info:eu-repo/grantAgreement/EC/H2020/680777/EU/Adaptable Reactors for Resource- and Energy-Efficient Methane Valorisation/ADREM$$9This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No H2020 680777-ADREM$$9info:eu-repo/grantAgreement/ES/MINECO/CTQ2017-87269-P
000087002 540__ $$9info:eu-repo/semantics/openAccess$$aby$$uhttp://creativecommons.org/licenses/by/3.0/es/
000087002 590__ $$a5.721$$b2019
000087002 591__ $$aCHEMISTRY, PHYSICAL$$b41 / 158 = 0.259$$c2019$$dQ2$$eT1
000087002 592__ $$a1.579$$b2019
000087002 593__ $$aCatalysis$$c2019$$dQ1
000087002 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion
000087002 700__ $$0(orcid)0000-0002-4546-4111$$aHueso, José L.
000087002 700__ $$aLara, Nidya
000087002 700__ $$aSole-Daura, Albert
000087002 700__ $$aPoblet, Josep M.
000087002 700__ $$0(orcid)0000-0003-4848-414X$$aMitchell, Scott G.$$uUniversidad de Zaragoza
000087002 700__ $$0(orcid)0000-0002-4758-9380$$aMallada, Reyes$$uUniversidad de Zaragoza
000087002 700__ $$0(orcid)0000-0002-8701-9745$$aSantamaría, Jesús$$uUniversidad de Zaragoza
000087002 7102_ $$15005$$2555$$aUniversidad de Zaragoza$$bDpto. Ing.Quím.Tecnol.Med.Amb.$$cÁrea Ingeniería Química
000087002 7102_ $$12013$$2765$$aUniversidad de Zaragoza$$bDpto. Química Orgánica$$cÁrea Química Orgánica
000087002 773__ $$g9, 21 (2019), 5927-5942$$pCATALYSIS SCIENCE & TECHNOLOGY$$tCATALYSIS SCIENCE & TECHNOLOGY$$x2044-4753
000087002 8564_ $$s5596892$$uhttps://zaguan.unizar.es/record/87002/files/texto_completo.pdf$$yVersión publicada
000087002 8564_ $$s57138$$uhttps://zaguan.unizar.es/record/87002/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada
000087002 909CO $$ooai:zaguan.unizar.es:87002$$particulos$$pdriver
000087002 951__ $$a2020-07-16-09:35:26
000087002 980__ $$aARTICLE