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The synthesis of high-silica BEA zeolite has attracted great attention from the zeolite scientific community, and several approaches have been proposed for the preparation of crystalline materials with a very low aluminum content. In this work, high-silica crystalline BEA zeolites were prepared starting from an Al-free synthesis gel, by using boron and iron as trivalent atoms. A Si/Fe molar ratio equal to 100, 200 or ∞ was adopted, and crystallization was successful in the presence of tetraethylammonium (TEA+), with a low Si/B starting synthesis gel molar ratio, i.e. 8 or 12, and with a hydrothermal synthesis time of 6 days maximum at 150 °C. The Si/Fe ratio affects TEA+–zeolite interactions, crystallographic patterns, and surface acidity. In particular, the proposed synthesis procedure allowed obtaining BEA zeolites with a very low acidity, with a tunable Lewis/Brønsted acids site distribution. Liquid-phase etherification of 5-hydroxymethyl furfural (HMF) with ethanol highlighted the suitability of the obtained materials for the production of 5-(ethoxymethyl)furan-2-carbaldeyde (EMF), a green fuel additive. Particularly, a high EMF selectivity (>97%) was obtained in the presence of both iron and boron. As the main outcome, the presented results indicated that high-silica BEA zeolite can be easily obtained starting from a low Si/B ratio in the synthesis gel, with conventional tetraethylammonium as a template, and iron can be also incorporated for catalytic purposes.

After short introducing the crucial role of e-fuels to meet net-zero emissions targets, this perspective paper discusses the differences between reactive catalysis (electro-, photo- and plasma-catalysis, with focus on the first for conciseness) and thermal catalysis used at most. The main point is to evidence that to progress in producing e-fuels, the gap is not in terms of scaling-up and pilot testing, but rather in the fundamental needs to turn the current approach and methodologies to develop reactive catalysis, including from a mechanistic perspective, to go beyond the current methods largely derived from thermal catalysis. Developing thus new fundamental bases to understand reactive catalysis is the challenge to accelerate the progress in this area to enable the potential role towards a sustainable net-zero emissions future. Some novel aspects are highlighted, but the general aim is rather to stimulate discussion in rethinking catalysis from an alternative perspective.

This perspective analyses last year's trends in green synthesis and sustainable processing routes from the viewpoint of the leading emerging industrial directions and needs. After briefly introducing the future scenario, the aspects discussed regard carbon neutrality and defossilization of the chemical industry, electrification of the processes and introduction of low-carbon H2routes. Some elements of artificial leaf and solar-to-X technologies, as well as e-chemistry, are also discussed. Trends, opportunities, and personal concerns regarding some directions are presented. The aim is to give clues to analyse this complex topic rather than offer a state-of-the-art and in-depth discussion of the presented examples.

The role of NH4+ion confinement in the catalytic etherification of HMF (5-hydroxymethylfurfural) with ethanol to biodiesel additives was evidenced by studying the catalytic behavior of NH4+-Beta zeolites with SiO2/Al2O3ratios of 25 and 75. In order to affect the strength and distribution of the acidic sites, as well as the mobility of NH4+ions in the zeolites cages, a secondary level of porosity was introduced in the NH4+-Beta, presenting a different stability versus alkaline treatment, by using a thermal or an ultrasound assisted method. By analyzing the catalytic behavior in these two series of samples with respect to the changes in porosity by nonlocal density functional theory, structure by XRD, amount of acid sites by FT-IR and mobility of NH4+cations by measurements of reversible NH4+exchange capacity, was evidenced a decrease in catalytic performances both in terms of rate of HMF depletion and productivity to the main products, when confinement of the ammonium ions is lost due to the introduction of mesoporosity. The high capability of ammonium ions release, associated to the mono-dentate configuration, and the minor confinement effect inside the zeolite pore system, due to the more opened pores structure of mesoporous zeolites, hinders both the direct etherification of HMF to EMF [5-(ethoxymethyl)furan-2-carbaldehyde] and the parallel reaction pathway via acetalization, favoring the rapid desorption of the HMFDEA [5-(hydroxymethyl)furfural diethyl acetal] product out of the crystal and the consequent inhibition of the consecutive reactions to EMFDEA [5-(ethoxymethyl)furfural diethyl acetal] and EMF.

The changing energy-chemistry nexus is discussed in this perspective paper about the future of sustainable energy and chemical production to identify the priorities and open issues on which focus research and development. Topics discussed regard (i) the new sustainable energy scenario, (ii) the role of energy storage (from smart grids to chemical storage of energy), (iii) the outlooks and role of solar (bio)refineries and solar fuels, (iv) how to integrate bio- and solar-refineries to move to new economy, (v) the role of methanol at the crossover of new energy-chemistry nexus, (vi) the role of chemistry in this new scenario, (vii) the role of nanomaterials for a sustainable energy, (viii) the use of nanocarbons to design advanced energy conversion and storage devices, and (ix) possibilities and routes to exploit solar energy and methane (shale gas). The contribution provides a glimpse of the emerging directions and routes with some elements about their possible role in the future scenario, but does not provide a detailed analysis of the state of the art in these directions.