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/A...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/Al2O3 ratios 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.展开更多
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...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.展开更多
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 developm...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 hio- 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 orovide a detailed analysis of the state of the art in these directions展开更多
文摘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/Al2O3 ratios 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.
基金supported by EU with ERC Synergy SCOPE(Surface-Confined Fast-modulated Plasma for Process and Energy Intensification in Small Molecules Conversion,810182)ProjectItalian MUR by PRIN 2017 Projects MULTI-e (Multielectron Transfer for the Conversion of Small Moleculesan Enabling Technology for the Chemical Use of Renewable Energy,20179337R7)CO_(2) ONLY (CO_(2) as Only Source of Carbons for Monomers and PolymersA Step Forwards Circular economy) Project,017WR2LRS
文摘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.
基金the PRIN10-11 projects "Mechanisms of activation of CO2for the design of new materials for energy and resource efficiency" and "Innovative processes for the conversion of algal biomass for the production of jet fuel and green diesel" for the financial support
文摘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 hio- 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 orovide a detailed analysis of the state of the art in these directions
