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One-pot combination of the in-situ generation of hydrogen peroxide (H2O2) with selective oxidation reactions enhances the environmental and economic attractiveness of the use of H2O2 as green oxidant at industrial scale. This tandem reaction improves not only the safety aspects associated to H2O2 storage and transportation but also reduces the capital and operation costs. This review covers the progress in the field focussing on the areas of catalysis development, mechanistic understanding and engineering approaches (such as membrane reactors) for specific systems involving epoxidation of propylene oxide, hydroxylation of benzene, oxygenate synthesis from methane and Fenton processes, highlighting the main challenges to overcome in the near future.

3 Figuras.- 5 tablas.-1 Esquema.- This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Sustainable Chemistry & Engineering, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acssuschemeng.5b01606 ”, The catalytic upgrading of crude bio-oils obtained through the pyrolysis of lignocellulosic biomass remarkably improves the properties of the final bio-oil. It has been demonstrated that the impregnation of hierarchically structured ZSM-5 zeolites with metal cations (Sn, Cu, Ni or Mg) promotes oxygen removal. Remarkably, the Mg-loaded hierarchical zeolite has led to the best fuel characteristics, achieving the greatest reduction in the oxygen-content and the lowest acidity. The promotion of ketonization reactions of acids with aldehydes to produce ketones seems to be favored over the Lewis acid sites created after incorporation of Mg cations at the ion exchange sites. A slightly lower deoxygenation rate is obtained for Cu-loaded hierarchical ZSM-5 zeolite. However, some subtle differences are identified. The most significant feature is the remarkable amount of evolved CO observed in the gas fraction. Thus, it could be assumed that decarbonylation of acids to aldehydes at Cu cations incorporated at ion exchange positions seems to be the prevalent deoxygenation reaction for this solid. Similarly, the preferential mechanism for O-removal using hierarchically structured Ni and Sn-ZSM-5 zeolites derived catalysts seems to proceed through decarbonylation and decarboxylation reactions at the metal acid Lewis sites. Although a prevalent reaction mechanism could not be identified, lower cation incorporation at ion exchange positions could explain the inferior deoxygenation rate. In all the cation-loaded hierarchical zeolites, the incorporation of metallic species at the ion exchange sites decreases the production of desired aromatics and this is linked with a lower amount of Brønsted acid sites., Authors thank to Spanish MINECO and European Union FEDER funds for providing support for this work (projects CTQ2012-37984-C02-01 and CTQ2012-37925-C03-02).

3 Tablae, 14 Figures.-- Supplementary material.-- © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/, The preparation and stabilization of gold nanoparticles with a precise control of size and dispersion is highly attractive for a variety of applications, and a key aspect is thermal stability of the nanoparticles. This paper focuses on understanding the effect of TiO2-based nanodomains, dispersed on mesoporous silicas, and how they control gold nanoparticle stability. The anatase domains have been incorporated through two different strategies: co-hydrolysis of Si and Ti reagents that directly form the mesoporous material through self-assembling with surfactant micelles, or the post-impregnation of the mesosporous silica with Ti(acac)2. Both strategies lead to different incorporation of the anatase domains: partially embedded inside the silica walls, or occupying the mesopores. We have observed that the inclusion in the pores favors the stability of the final material due to a more favorable gold-support interaction and also due to a stabilizing effect associated with a scaffold effect of the anatase crystals, which hinders the collapse of the mesostructure., This research was supported by the Spanish Ministerio de Economia y Competitividad and European Feder Funds (MAT2015-64139-C4-3-R, ENE2015-68320-R). The TEM measurements were performed in the Laboratorio de Microscopias Avanzadas (LMA) at the Instituto de Nanociencia de Aragon (INA) - Universidad de Zaragoza (Spain) and received funding from the European Union Seventh Framework Program under Grant Agreement 312483 - ESTEEM2 (Integrated Infrastructure Initiative - I3). B. Puértolas thanks the Ministry of Education for FPU grant (FPU grant AP2009-3544). A. Moragues thanks the Ministry of Economia y Competitividad for FPI grant (FPI grant BES2009-040029). UV is also acknowledged by the UV-INV-AE16-484416 project.