02645nas a2200289 4500008004100000022001400041245012500055210006900180260000800249300001600257490000700273520167000280653001201950653002501962653001401987653002702001653002102028653001902049100002202068700002602090700002202116700001802138700002902156700002402185700001902209856012702228 2021 eng d a2155-543500aSupported MoOx and WOx solid acids for biomass valorization: interplay of coordination chemistry, acidity, and catalysis0 aSupported MoOx and WOx solid acids for biomass valorization inte cNOV a13603-136480 v113 aSupported molybdenum oxide (MoOx) and tungsten oxide (WOx) materials are a vital class of solid acid catalysts for the chemical industry because of their nontoxic nature, strong acidity, remarkable stability in water, hydrogen, and oxygen atmospheres, and excellent reusability performance. These fascinating solid acids play a pivotal role in developing sustainable catalytic routes for renewable biomass processing to produce value-added fuels, chemicals, and platform molecules. The coordination chemistry of MoOx and WOx on the support materials (oxides, carbons, or zeolites) controls their acidic strength, active site accessibility, and catalytic activity. Hence, significant efforts have been made toward optimizing the conditions used for catalyst synthesis and biomass processing to tune the coordination chemistry of MoOx and WOx with the substrate molecules and, thus, their acid-activity/selectivity performance. This Review provides a comprehensive overview of supported MoOx and WOx solid acids for biomass valorization. The importance of the biomass and the role of solid acids for biomass valorization were emphasized, followed by a brief discussion of supported MoOx and WO(x )solid acids. Afterward, the interplay of coordination chemistry, acidic strength, and catalytic activity of supported MoOx and WOx solid acids was discussed. Finally, their catalytic applications for the valorization of several biomass substrates and their derivatives were summarized. This Review will provide valuable insights for developing advanced supported WOx and MoOx solid acids for catalytic biomass valorization and other challenging acid-catalyzed processes.10aAcidity10abiomass valorization10acatalysis10aCoordination chemistry10amolybdenum oxide10atungsten oxide1 aSudarsanam, Putla1 aGupta, Navneet, Kumar1 aMallesham, Baithy1 aSingh, Nittan1 aKalbande, Pavan, Narayan1 aReddy, Benjaram, M.1 aSels, Bert, F. uhttp://library.ncl.res.in/content/supported-moox-and-wox-solid-acids-biomass-valorization-interplay-coordination-chemistry02360nas a2200253 4500008004100000022001400041245013400055210006900189260000800258300001100266490000800277520142800285653002801713653003101741653003401772653003701806653002701843653001901870100001801889700002901907700002401936700002201960856012401982 2022 eng d a2468-823100aEfficient cascade C-N coupling reactions catalyzed by a recyclable MoOx/ Nb2O5 nanomaterial for valuable N-heterocycles synthesis0 aEfficient cascade CN coupling reactions catalyzed by a recyclabl cNOV a1127420 v5323 a

The efficient cascade synthesis of pharmaceutically valuable N-heterocycles at solvent-free conditions was achieved using a robust, recyclable MoOx/Nb2O5 nanocatalyst. The results of catalyst screening revealed that the MoOx/Nb2O5 nanorods, calcined at 500 degrees C (MoNb5), exhibit excellent catalytic activity in the oxidative coupling of benzylamine with 96.5% conversion and >99.6% selectivity to the desirable imine product. The uniform dispersion of Mo-oxide nanoparticles (average particle size: 5.2 +/- 0.5 nm) on shape-controlled Nb2O5 nanorods (width: 5.3 +/- 0.5 nm and length: 23-38 nm) in MoNb5 catalyst led to improved structural and acid properties, beneficial for the cascade C-N bond construction. The shape-controlled MoNb5 catalyst showed versatile activity in various cascade C-N coupling reactions to obtain 2-phenylbenzimidazole, 2-phenyl-quinaxoline, and 2-phenyl-2,3-dihydroquinazolin-4(1H)-one with good to excellent yields at solvent-free con-ditions. The optimum ratio of Lewis/Bronsted acid sites, the unique structure of Nb2O5 nanorods, and the strong MoO3-Nb2O5 interaction are the key reasons for the higher activity of MoNb5 catalyst. The efficient reusability of MoNb5 catalyst, its remarkable activity in diverse N-heterocycles synthesis, and efficient gram-scale synthesis emphasize its practical application for the cascade C-N coupling reactions under benign conditions.

10aAcid sites optimization10aCascade C-N bond formation10aDiverse nitrogenous chemicals10aHeterogeneous nanosized catalyst10aMoO3-Nb2O5 interaction10aNb2O5 nanorods1 aSingh, Nittan1 aKalbande, Pavan, Narayan1 aUmbarkar, Shubhangi1 aSudarsanam, Putla uhttp://library.ncl.res.in/content/efficient-cascade-c-n-coupling-reactions-catalyzed-recyclable-moox-nb2o5-nanomaterial01524nas a2200229 4500008004100000022001400041245009400055210006900149260000800218300001100226490000800237520072900245653001900974653001600993653003301009653002601042653003401068100002201102700001801124700002901142856012301171 2022 eng d a1566-736700aShape-controlled nanostructured MoO3/CeO2 catalysts for selective cyclohexene epoxidation0 aShapecontrolled nanostructured MoO3CeO2 catalysts for selective  cAPR a1064330 v1643 a

This study reported a vital role of CeO2 shape on the structure-activity properties of MoOx/CeO2 catalysts for cyclohexene epoxidation. Uniform dispersion of MoOx on the surface of shape-controlled CeO2 nanocubes (average particle size: 23.5 nm) and nanorods (average width: 6.3 nm and length: 15-95 nm) was found in MoOx/CeO2 nanomaterials. The MoOx/CeO2 nanocubes showed higher epoxide selectivity (97.3%) with 98.9% cyclohexene conversion, although it has lower BET surface area (30.2 m(2)/g) compared with MoOx/CeO2 nanorods (72.8 m(2)/g). The presence of more electropositive Mo6+ species and the strong Mo-Ce interaction led to improved catalytic efficacy of MoOx/CeO2 nanocubes in cyclohexene epoxidation.

10aCeO2 nanocubes10aCeO2 shapes10aNanosized MoOx/CeO2 catalyst10aSelective epoxidation10aStructure-activity properties1 aSudarsanam, Putla1 aSingh, Nittan1 aKalbande, Pavan, Narayan uhttp://library.ncl.res.in/content/shape-controlled-nanostructured-moo3ceo2-catalysts-selective-cyclohexene-epoxidation01729nas a2200253 4500008004100000022001400041245013600055210006900191260000800260300001100268490000800279520081600287653002501103653002901128653002501157653001801182653003501200100002901235700001801264700001901282700002401301700002201325856012801347 2023 eng d a1566-736700aOne-pot synthesized efficient molybdenum-niobium-oxide nanocatalyst for selective C-O and C-N coupling reactions at mild conditions0 aOnepot synthesized efficient molybdenumniobiumoxide nanocatalyst cOCT a1067660 v1833 a

An efficient molybdenum-niobium-oxide nanomaterial was synthesized by a one-pot hydrothermal method for selective C-O (glycerol ketalization) and C-N coupling (benzylamine oxidation) reactions. The catalytically favourable properties, such as defective metal sites, truncated surfaces, and uniform metal dispersion in the MoO3-Nb2O5 nanorods, calcined at 500 degrees C (MoNb OPS-5), were confirmed by Raman, HR-TEM, and STEM-EDX, respectively. Because of improved Lewis/Bronsted acidic strength, the MoNb OPS-5 catalyst showed higher activity in glycerol ketalization and benzylamine oxidation at mild conditions, giving superior selectivity to solketal (97%) and dibenzylimine (99%), respectively. The MoNb OPS-5 catalyst showed high structural stability and considerable good reusability efficacy.

10aC-O and C-N coupling10aGlycerol and benzylamine10aMo-Nb-O nanocatalyst10ananocatalysts10aOne-pot hydrothermal synthesis1 aKalbande, Pavan, Narayan1 aSingh, Nittan1 aSwapna, Bhattu1 aUmbarkar, Shubhangi1 aSudarsanam, Putla uhttp://library.ncl.res.in/content/one-pot-synthesized-efficient-molybdenum-niobium-oxide-nanocatalyst-selective-c-o-and-c-n