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Environmental assessments in green chemistry often rely on simplified metrics that enable comparisons between alternative routes but fail to shed light on whether they are truly sustainable in absolute terms, viz. relative to the Earth's ecological capacity. To expand our currently limited knowledge of the extent to which chemicals are environmentally sustainable, here we analyse 492 chemical products through the lens of seven planetary boundaries representing critical biophysical limits that should never be exceeded. We found that most of them transgress these environmental guardrails, mainly the ones strongly connected to greenhouse gas emissions (i.e., climate change, ocean acidification and biosphere integrity). However, their levels of transgression fail to correlate with their carbon footprints, currently the focus of most studies, implying that chemicals entailing higher greenhouse gas emissions are not necessarily less environmentally sustainable in absolute terms. Our work points towards the need to embrace absolute sustainability criteria in current environmental assessments, which will require agreeing on how to allocate shares of the planet's ecological capacity among anthropogenic activities, including chemicals' production. This work's absolute environmental sustainability assessment (AESA) method, which could complement standard life cycle assessment approaches, might help experimental researchers working in green chemistry develop truly 'green' products. The AESA method should be taken as a starting point to devise holistic approaches for quantifying the absolute environmental impact of chemicals to guide research and policymaking more sensibly. [ABSTRACT FROM AUTHOR]

The use of ethane as a platform molecule for the manufacture of polyvinyl chloride (PVC) is a longstanding challenge, which would allow to reduce the raw material costs and CO2 emissions to produce this plastic. Herein, we discover that rare earth oxychlorides catalyze in a selective (up to 90 %) and stable (>50 h on stream) manner the reaction of ethane and molecular chlorine into 1,2‐dichloroethane, which, upon established cracking, will translate into an order of magnitude higher vinyl chloride productivity compared to ethane oxychlorination technologies. In addition, representative europium oxychloride was supported on suitable carriers and was demonstrated to be selective (up to 90 %) and stable (>40 h on stream) in extrudate form. These findings bring the ethane‐based production of PVC one step closer to implementation. [ABSTRACT FROM AUTHOR]

The use of ethane as a platform molecule for the manufacture of polyvinyl chloride (PVC) is a longstanding challenge, which would allow to reduce the raw material costs and CO2 emissions to produce this plastic. Herein, we discover that rare earth oxychlorides catalyze in a selective (up to 90 %) and stable (>50 h on stream) manner the reaction of ethane and molecular chlorine into 1,2‐dichloroethane, which, upon established cracking, will translate into an order of magnitude higher vinyl chloride productivity compared to ethane oxychlorination technologies. In addition, representative europium oxychloride was supported on suitable carriers and was demonstrated to be selective (up to 90 %) and stable (>40 h on stream) in extrudate form. These findings bring the ethane‐based production of PVC one step closer to implementation. [ABSTRACT FROM AUTHOR]

Back Cover: Ethane-Based Catalytic Process for Vinyl Chloride Manufacture (Angew. Catalytic ethane chlorination, ethylene dichloride, natural gas, polyvinyl chloride, rare-earth oxychlorides Keywords: catalytic ethane chlorination; ethylene dichloride; natural gas; polyvinyl chloride; rare-earth oxychlorides EN catalytic ethane chlorination ethylene dichloride natural gas polyvinyl chloride rare-earth oxychlorides 24332 24332 1 10/27/21 20211102 NES 211102 B Gas-to-PVC b In their Research Article on page 24162, Guido Zichittella and Javier Pérez-Ramírez show the outstanding performance of rare earth oxychloride catalysts for the selective conversion of ethane into 1,2-dichloroethane, a precursor of vinyl chloride monomer. [Extracted from the article]

Rücktitelbild: Ethane-Based Catalytic Process for Vinyl Chloride Manufacture (Angew. Catalytic ethane chlorination, ethylene dichloride, natural gas, polyvinyl chloride, rare-earth oxychlorides Keywords: catalytic ethane chlorination; ethylene dichloride; natural gas; polyvinyl chloride; rare-earth oxychlorides EN catalytic ethane chlorination ethylene dichloride natural gas polyvinyl chloride rare-earth oxychlorides 24536 24536 1 10/27/21 20211102 NES 211102 B Gas-to-PVC b Im Forschungsartikel auf S. 24291 berichten Guido Zichittella und Javier Pérez-Ramírez über die herausragende Aktivität von Seltenerd-Oxychlorid-Katalysatoren für die selektive Umwandlung von Ethan in 1,2-Dichlorethan, einen Vorläufer des Vinylchlorid-Monomers. [Extracted from the article]

Chemistry, a vital tool for sustainable development, faces a challenge due to the lack of clear guidance on actionable steps, hindering the optimal adoption of sustainability practices across its diverse facets from discovery to implementation. This Scientific Perspective explores established frameworks and principles, proposing a conciliated set of triple E priorities anchored on Environmental, Economic, and Equity pillars for research and decision making. We outline associated metrics, crucial for quantifying impacts, classifying them according to their focus areas and scales tackled. Emphasizing catalysis as a key driver of sustainable synthesis of chemicals and materials, we exemplify how triple E priorities can practically guide the development and implementation of processes from renewables conversions to complex customized products. We summarize by proposing a roadmap for the community aimed at raising awareness, fostering academia–industry collaboration, and stimulating further advances in sustainable chemical technologies across their broad scope. [ABSTRACT FROM AUTHOR]

Chemistry, a vital tool for sustainable development, faces a challenge due to the lack of clear guidance on actionable steps, hindering the optimal adoption of sustainability practices across its diverse facets from discovery to implementation. This Scientific Perspective explores established frameworks and principles, proposing a conciliated set of triple E priorities anchored on Environmental, Economic, and Equity pillars for research and decision making. We outline associated metrics, crucial for quantifying impacts, classifying them according to their focus areas and scales tackled. Emphasizing catalysis as a key driver of sustainable synthesis of chemicals and materials, we exemplify how triple E priorities can practically guide the development and implementation of processes from renewables conversions to complex customized products. We summarize by proposing a roadmap for the community aimed at raising awareness, fostering academia–industry collaboration, and stimulating further advances in sustainable chemical technologies across their broad scope. [ABSTRACT FROM AUTHOR]

New and enhanced processes will not be the only drivers toward a sustainable chemical industry. Implementing climate policies will impact all components of the chemical supply chain over the following decades, making improvements in energy generation, material extraction, or transportation contribute to reducing the overall impacts of chemical technologies. Including this synergistic effect when comparing technologies offers a clearer vision of their future potential and may allow researchers to support their sustainability propositions more strongly. Ammonia and methanol production account for more than fifty percent of the CO2 emissions in this industry and are, therefore, excellent case studies. This work performs a prospective life cycle assessment until 2050 for fossil, blue, wind, and solar-based technologies under climate policies aiming to limit the global temperature rise to 1.5 °C, 2 °C, or 3.5 °C. The first finding is the inability of fossil-based routes to reduce their CO2 emissions beyond 10% by 2050 without tailored decarbonisation strategies, regardless of the chemical and climate policy considered. In contrast, green routes may produce chemicals with around 90% fewer emissions than today and even with net negative emissions (on a cradle-to-gate basis), as in the case of methanol (up to −1.4 kg CO2-eq per kg), mainly due to the contributions of technology development and increasing penetration of renewable energies. Overall, the combined production of these chemicals could be net-zero by 2050 despite their predicted two to fivefold increase in demand. Lastly, we propose a roadmap for progressive implementation by 2050 of green routes in 26 regions worldwide, applying the criterion of at least 80% reduction in climate change impacts when compared to their fossil alternatives. Furthermore, an exploratory prospective techno-economic assessment showed that by 2050, green routes could become more economically attractive. This work offers quantitative arguments to reinforce research, development, and policymaking efforts on green chemical routes reliant on renewable energies. [ABSTRACT FROM AUTHOR]

Single‐atom heterogeneous catalysts (SACs) hold promise as sustainable alternatives to metal complexes in organic transformations. However, their working structure and dynamics remain poorly understood, hindering advances in their design. Exploiting the unique features of droplet‐based microfluidics, we present the first in‐situ assessment of a palladium SAC based on exfoliated carbon nitride in Suzuki–Miyaura cross‐coupling using X‐ray absorption spectroscopy. Our results confirm a surface‐catalyzed mechanism, revealing the distinct electronic structure of active Pd centers compared to homogeneous systems, and providing insights into the stabilizing role of ligands and bases. This study establishes a valuable framework for advancing mechanistic understanding of organic syntheses catalyzed by SACs. [ABSTRACT FROM AUTHOR]

Single‐atom heterogeneous catalysts (SACs) hold promise as sustainable alternatives to metal complexes in organic transformations. However, their working structure and dynamics remain poorly understood, hindering advances in their design. Exploiting the unique features of droplet‐based microfluidics, we present the first in‐situ assessment of a palladium SAC based on exfoliated carbon nitride in Suzuki–Miyaura cross‐coupling using X‐ray absorption spectroscopy. Our results confirm a surface‐catalyzed mechanism, revealing the distinct electronic structure of active Pd centers compared to homogeneous systems, and providing insights into the stabilizing role of ligands and bases. This study establishes a valuable framework for advancing mechanistic understanding of organic syntheses catalyzed by SACs. [ABSTRACT FROM AUTHOR]

C1 coupling reactions over zeolite catalysts are central to sustainable chemical production strategies. However, questions persist regarding the involvement of CO in ketene formation, and the impact of this elusive oxygenate intermediate on reactivity patterns. Using operando photoelectron photoion coincidence spectroscopy (PEPICO), we investigate the role of CO in methyl chloride conversion to hydrocarbons (MCTH), a prospective process for methane valorization with a reaction network akin to methanol to hydrocarbons (MTH) but without oxygenate intermediates. Our findings reveal the transformative role of CO in MCTH at the low pressures, inducing ketene formation in MCTH and boosting olefin production, confirming the Koch carbonylation step in the initial stages of C1 coupling. We uncover pressure‐dependent product distributions driven by CO‐induced ketene formation, and its subsequent desorption from the zeolite surface, which is enhanced at low pressure. Inspired by the above results, extension of the co‐feeding approach to CH3OH as another simple oxygenate showcases the additional potential for improved catalyst stability in MCTH at ambient pressure. [ABSTRACT FROM AUTHOR]

C1 coupling reactions over zeolite catalysts are central to sustainable chemical production strategies. However, questions persist regarding the involvement of CO in ketene formation, and the impact of this elusive oxygenate intermediate on reactivity patterns. Using operando photoelectron photoion coincidence spectroscopy (PEPICO), we investigate the role of CO in methyl chloride conversion to hydrocarbons (MCTH), a prospective process for methane valorization with a reaction network akin to methanol to hydrocarbons (MTH) but without oxygenate intermediates. Our findings reveal the transformative role of CO in MCTH at the low pressures, inducing ketene formation in MCTH and boosting olefin production, confirming the Koch carbonylation step in the initial stages of C1 coupling. We uncover pressure‐dependent product distributions driven by CO‐induced ketene formation, and its subsequent desorption from the zeolite surface, which is enhanced at low pressure. Inspired by the above results, extension of the co‐feeding approach to CH3OH as another simple oxygenate showcases the additional potential for improved catalyst stability in MCTH at ambient pressure. [ABSTRACT FROM AUTHOR]

Catalytic hydrogenolysis has the potential to convert high‐density polyethylene (HDPE), which comprises about 30 % of plastic waste, into valuable alkanes. Most investigations have focused on increasing activity for lab grade HDPEs displaying low molecular weight, with limited mechanistic understanding of the product distribution. No efficient catalyst is available for consumer grades due to their lower reactivity. This study targets HDPE used in bottle caps, a waste form generated globally at a rate of approximately one million units per hour. Ultrafine ruthenium particles (1 nm) supported on titania (anatase) achieved up to 80 % conversion into light alkanes (C1−C45) under mild conditions (498 K, 20 bar H2, 4 h) and were reused for three cycles. Small ruthenium nanoparticles were critical to achieving relevant conversions, as activity sharply decreased with particle size. Selectivity commonalities and peculiarities across HDPE grades were disclosed by a reaction modelling approach applied to products. Isomerization cedes to backbone scission as the reaction progresses. Within this trend, low molecular weight favor isomerization whilst high molecular weight favor cleavage. Commercial caps obeyed this trend with decreased activity, anticipating the influence of additives in realistic processing. This study demonstrates effective hydrogenolysis of consumer grade polyethylene and provides selectivity patterns for product control. [ABSTRACT FROM AUTHOR]

Catalytic hydrogenolysis has the potential to convert high‐density polyethylene (HDPE), which comprises about 30 % of plastic waste, into valuable alkanes. Most investigations have focused on increasing activity for lab grade HDPEs displaying low molecular weight, with limited mechanistic understanding of the product distribution. No efficient catalyst is available for consumer grades due to their lower reactivity. This study targets HDPE used in bottle caps, a waste form generated globally at a rate of approximately one million units per hour. Ultrafine ruthenium particles (1 nm) supported on titania (anatase) achieved up to 80 % conversion into light alkanes (C1−C45) under mild conditions (498 K, 20 bar H2, 4 h) and were reused for three cycles. Small ruthenium nanoparticles were critical to achieving relevant conversions, as activity sharply decreased with particle size. Selectivity commonalities and peculiarities across HDPE grades were disclosed by a reaction modelling approach applied to products. Isomerization cedes to backbone scission as the reaction progresses. Within this trend, low molecular weight favor isomerization whilst high molecular weight favor cleavage. Commercial caps obeyed this trend with decreased activity, anticipating the influence of additives in realistic processing. This study demonstrates effective hydrogenolysis of consumer grade polyethylene and provides selectivity patterns for product control. [ABSTRACT FROM AUTHOR]

Ternäre Pd‐In2O3/ZrO2 Katalysatoren beweisen technologisches Potenzial für die CO2‐basierte Methanolsynthese, wobei die Entwicklung skalierbarer Systeme und das Verständnis komplexer dynamischer Wechselwirkungen zwischen der aktiven Phase, des Promotors und des Trägers der Schlüssel zur Erreichung einer hohen Produktivität sind. Hier zeigen wir, dass durch einfache Imprägnierung hergestellte Pd‐In2O3/ZrO2 Katalysatoren unter CO2‐Hydrierbedingungen eine stabile und selektive Nanoarchitektur bilden, unabhängig von der Reihenfolge der Zugabe von Pd‐ und In‐Komponenten auf den Zirkonoxidträger. Detaillierte operando Charakterisierung und Simulationen deuten auf eine schnelle Umstrukturierung, dessen Treiber die Energie der Metall‐Metalloxid‐Wechselwirkung ist. Die Nähe von InOx‐Schichten auf den entstehenden InPdx‐Partikeln verhindern Leistungsverluste durch Pd‐Sinterung. Weiterhin unterstreichen die Ergebnisse die entscheidende Rolle der reaktionsinduzierten Umstrukturierung in komplexem CO2‐Hydrierkatalysatoren und bieten Einblicke in die optimale Integration von Säure‐Base‐ und Redoxfunktionen für die technische Umsetzung. [ABSTRACT FROM AUTHOR]

Ternary Pd‐In2O3/ZrO2 catalysts exhibit technological potential for CO2‐based methanol synthesis, but developing scalable systems and comprehending complex dynamic behaviors of the active phase, promoter, and carrier are key for achieving high productivity. Here, we show that the structure of Pd‐In2O3/ZrO2 systems prepared by wet impregnation evolves under CO2 hydrogenation conditions into a selective and stable architecture, independent of the order of addition of Pd and In phases on the zirconia carrier. Detailed operando characterization and simulations reveal a rapid restructuring driven by the metal‐metal oxide interaction energetics. The proximity of InPdx alloy particles decorated by InOx layers in the resulting architecture prevents performance losses associated with Pd sintering. The findings highlight the crucial role of reaction‐induced restructuring in complex CO2 hydrogenation catalysts and offer insights into the optimal integration of acid‐base and redox functions for practical implementation. [ABSTRACT FROM AUTHOR]

Ammonia and methanol are essential to modern societies, but their production has been heavily reliant on natural gas, which contributes to supply disruptions and significant CO2 emissions. While low-carbon or green production routes have been extensively researched, their adoption has been hindered by higher costs, making them unsustainable. However, a recent energy crisis in Europe has created a unique opportunity to shift towards greener production technologies. Here we show that, green ammonia, produced through wind-powered water electrolysis, had the potential to outperform its fossil counterpart for six months as of December 2021, while methanol produced through CO2 capture and wind-based water electrolysis became an economically appealing alternative. With a coordinated effort from academia, industry, and policymakers, Europe can lead the grand transition towards more sustainable practices in the chemical industry. [ABSTRACT FROM AUTHOR]

Recently discovered phosphate-derived Ni catalysts have opened a new pathway towards multicarbon products via CO2 electroreduction. However, understanding the influence of basic parameters such as electrode potential, pH, and buffer capacity is needed for optimized C3+ product formation. To this end, rigorous catalyst evaluation and sensitive analytical tools are required to identify potential new products and minimize increasing quantification errors linked to long-chain carbon compounds. Herein, we contribute to enhance testing accuracy by presenting sensitive 1H NMR spectroscopy protocols for liquid product assessment featuring optimized water suppression and reduced experiment time. When combined with an automated NMR data processing routine, samples containing up to 12 products can be quantified within 15 min with low quantification limits equivalent to Faradaic efficiencies of 0.1%. These developments disclosed performance trends in carbon product formation and the detection of four hitherto unreported compounds: acetate, ethylene glycol, hydroxyacetone, and i-propanol. Phosphate-derived nickel catalysts enable access to multicarbon products via CO2 electroreduction, but it remains unclear how operating conditions influence product formation. Here, refined 1H NMR spectroscopy protocols are introduced and combined with an automated NMR data processing routine, enabling quantification of carbon product formation as a function of various parameters. [ABSTRACT FROM AUTHOR]

Mixed zinc‐zirconium oxides, ZnZrOx, are highly selective and stable catalysts for CO2 hydrogenation to methanol, a pivotal energy vector. However, their activity remains moderate, and descriptors to design improved systems are lacking. This work applies flame spray pyrolysis (FSP), a one‐step and scalable method, to synthesize a series of ZnZrOx catalysts, and systematically compares them to coprecipitated (CP) analogs to establish deeper synthesis–structure–performance relationships. FSP systems (up to 5 mol%) generally display a threefold higher methanol productivity compared to their CP counterparts. In‐depth characterization and theoretical simulations show that, unlike CP, FSP maximizes the surface area and formation of atomically dispersed Zn2+ sites incorporated in lattice positions within the ZrO2 surface, which is key to improving performance. Analysis by in situ electron paramagnetic resonance (EPR) spectroscopy reveals that the specific architecture of the flame‐made catalyst markedly fosters the generation of oxygen vacancies. Together with surrounding Zn and Zr‐O atoms, the oxygen vacancies create active ensembles that favor methanol formation through the formate path while suppressing undesired CO production, as confirmed by kinetic modeling. This study elucidates the nature of active sites and their working mechanism, pushing forward ZnZrOx‐catalyzed methanol synthesis by providing a new benchmark for this cost‐effective and earth‐abundant catalyst family. [ABSTRACT FROM AUTHOR]

Bimetallic single–atom catalysts (b–SACs) have recently gained prominence by virtue of the unique catalytic cooperative interactions they can exhibit, intertwining electronic and geometric effects. To date, research efforts have exclusively focused on direct mechanisms such as electron density transfer or sequential reactivity. Herein, the first study on indirect, coordination–induced catalytic synergies in carbon‐supported RuPt SACs is conducted. To this end, a holistic approach is developed, combining i) precision synthesis, ii) advanced characterization, iii) exploration of single–site adsorption properties via the hydrogen evolution reaction, and iv) modeling through density functional theory. Despite the lack of both intermetallic coordination in the first or second shell and charge redistribution effects, the RuPt SACs exhibit a H2 formation rate enhanced up to 15–fold compared with their monometallic counterparts. To unfold the origin of the intermetallic cooperativity, modifications of the structural and catalytic properties induced by the integration of a second metal species are investigated. Thus, Pt atoms are found to selectively occupy the most energeticallyfavorable cavities in the support, prompting Ru atoms to assume a distinct, more active, configuration. This contribution unveils a novel principle of bimetallic cooperativity, demonstrating the key role of integrative experimental and computational analyses in studying b–SACs. [ABSTRACT FROM AUTHOR]

Thermocatalytic CO 2 hydrogenation to methanol is an attractive defossilization technology to combat climate change while producing a valuable platform chemical and energy carrier. However, predicting the performance of catalytic systems for this process remains a challenge. Herein, we present a machine learning framework to predict catalyst performance from experimental descriptors. A database of Cu-, Pd-, In 2 O 3 -, and ZnO-ZrO 2 -based catalysts with 1425 datapoints is compiled from literature and subjected to data mining. Accurate ensemble-tree models (R 2 > 0.85) are developed to predict the methanol space-time yield (STY) from 12 descriptors, where the significance of space velocity, pressure, and metal content is revealed. The model prediction and its insights are experimentally validated, with a root mean squared error of 0.11 g MeOH h−1 g cat −1 between the actual and predicted methanol STY. The framework is purely data-driven, interpretable, cross-deployable to other catalytic processes, and serves as an invaluable tool for guided experiments and optimization. [Display omitted] • Machine learning framework for CO 2 hydrogenation to methanol devised. • Database for Cu-, Pd-, In 2 O 3 - and ZnO-ZrO 2 -based catalysts compiled. • Generalized model to predict methanol space-time yield (STY) developed. • Efficacy and fidelity of the model experimentally validated. • Model enhancements to aid the discovery of novel catalysts required. [ABSTRACT FROM AUTHOR]

Solar‐driven transfer hydrogenation of unsaturated bonds has received considerable attention in the research area of sustainable organic synthesis; however, water, the ultimate green source of hydrogen, has rarely been investigated due to the high barrier associated with splitting of water molecules. We report a carbon‐nitride‐supported palladium single‐atom heterogeneous catalyst with unparalleled performance in photocatalytic water‐donating transfer hydrogenation compared to its nanoparticle counterparts. Isotopic‐labeling experiments and operando nuclear magnetic resonance measurements confirm the direct hydrogenation mechanism using in situ‐generated protons from water splitting under visible‐light irradiation. Density functional theory calculations attribute the high activity to lower barriers for hydrogenation, facilitated desorption of ethylbenzene, and facile hydrogen replenishment from water on the atomic palladium sites. [ABSTRACT FROM AUTHOR]

Solar‐driven transfer hydrogenation of unsaturated bonds has received considerable attention in the research area of sustainable organic synthesis; however, water, the ultimate green source of hydrogen, has rarely been investigated due to the high barrier associated with splitting of water molecules. We report a carbon‐nitride‐supported palladium single‐atom heterogeneous catalyst with unparalleled performance in photocatalytic water‐donating transfer hydrogenation compared to its nanoparticle counterparts. Isotopic‐labeling experiments and operando nuclear magnetic resonance measurements confirm the direct hydrogenation mechanism using in situ‐generated protons from water splitting under visible‐light irradiation. Density functional theory calculations attribute the high activity to lower barriers for hydrogenation, facilitated desorption of ethylbenzene, and facile hydrogen replenishment from water on the atomic palladium sites. [ABSTRACT FROM AUTHOR]

Chemistry is vital for society , but its practices must align with sustainable development. While attention often focuses on individual pillars—environment, economy, or equity—true sustainability requires alignment across all three. The cover image depicts a sustainability compass, symbolizing the integration of diverse principles into a unified set of triple E priorities proposed by Javier Pérez‐Ramírez et al. in their Scientific Perspective (e202318676) to guide efforts in the chemical sciences...By Sharon Mitchell; Antonio J. Martín; Gonzalo Guillén‐Gosálbez and Javier Pérez‐RamírezReported by Author; Author; Author; Author [Extracted from the article]

Chemistry is vital for society , but its practices must align with sustainable development. While attention often focuses on individual pillars—environment, economy, or equity—true sustainability requires alignment across all three. The cover image depicts a sustainability compass, symbolizing the integration of diverse principles into a unified set of triple E priorities proposed by Javier Pérez‐Ramírez et al. in their Scientific Perspective (e202318676) to guide efforts in the chemical sciences...By Sharon Mitchell; Antonio J. Martín; Gonzalo Guillén‐Gosálbez and Javier Pérez‐RamírezReported by Author; Author; Author; Author [Extracted from the article]

The article titled "Titelbild: Droplet-Based Microfluidics Reveals Insights into Cross-Coupling Mechanisms over Single-Atom Heterogeneous Catalysts" discusses the development of in-situ characterization tools for heterogeneous catalysts in organic syntheses. The authors, Andrew J. deMello, Javier Pérez-Ramírez, Sharon Mitchell, and their colleagues, demonstrate the use of an innovative in-situ X-ray absorption spectroscopy approach using droplet-based microfluidics to study palladium single-atom catalysts in Suzuki-Miyaura coupling. The results of their study highlight the feasibility of this technique and its potential to provide new mechanistic insights. Additionally, the article mentions another research article by Shungui Zhou, Yujie Xiong, and their colleagues, which reports on the discovery of non-Fenton-type reactive oxygen species driving abiotic CH4 production, offering a new approach for engineering CH4 production. [Extracted from the article]

The article discusses the importance of developing improved in-situ characterization tools for designing heterogeneous catalysts for organic syntheses. The authors present an innovative in-situ X-ray absorption spectroscopy approach using droplet-based microfluidics to study palladium single-atom catalysts in Suzuki-Miyaura coupling. The results demonstrate the feasibility of the technique and its potential to provide new mechanistic insights. Additionally, another research article by different authors explores the discovery of non-Fenton-type reactive oxygen species driving abiotic CH4 production, offering a new approach for engineering CH4 production. [Extracted from the article]

The production of nitrous oxide, N2O, via NH3 oxidation is not on a practical scale due to the lack of a suitable catalyst. Instead, it is produced via thermal decomposition of NH4NO3, rendering N2O too costly and limiting its prospective uses. Herein, we report CeO2‐supported Au nanoparticles (2–3 nm) as a highly selective catalyst for low‐temperature NH3 oxidation to N2O, exhibiting two orders of magnitude higher space–time yield than the state‐of‐the‐art Mn−Bi/α‐Al2O3 and remarkable stability over 70 h on stream. The reaction proceeds via a Mars–van Krevelen mechanism, with the density of interfacial Auδ+ species and the oxygen storage capacity of CeO2 identified as the key performance descriptors. The latter could be enhanced by cobalt doping, improving the catalytic activity and setting a new benchmark for N2O productivity. These findings establish NH3 oxidation as an efficient process for N2O manufacture and facilitate its broader utilization in selective oxidations. [ABSTRACT FROM AUTHOR]

The production of nitrous oxide, N2O, via NH3 oxidation is not on a practical scale due to the lack of a suitable catalyst. Instead, it is produced via thermal decomposition of NH4NO3, rendering N2O too costly and limiting its prospective uses. Herein, we report CeO2‐supported Au nanoparticles (2–3 nm) as a highly selective catalyst for low‐temperature NH3 oxidation to N2O, exhibiting two orders of magnitude higher space–time yield than the state‐of‐the‐art Mn−Bi/α‐Al2O3 and remarkable stability over 70 h on stream. The reaction proceeds via a Mars–van Krevelen mechanism, with the density of interfacial Auδ+ species and the oxygen storage capacity of CeO2 identified as the key performance descriptors. The latter could be enhanced by cobalt doping, improving the catalytic activity and setting a new benchmark for N2O productivity. These findings establish NH3 oxidation as an efficient process for N2O manufacture and facilitate its broader utilization in selective oxidations. [ABSTRACT FROM AUTHOR]

A plethora of metal promoters have been applied to enhance the performance of In2O3 in CO2 hydrogenation to methanol, a prospective energy carrier. However, the lack of systematic catalyst preparation and evaluation precludes a direct comparison of their speciation and promotional effects, and consequently, the design of an optimal system. Herein, flame spray pyrolysis (FSP) is employed as a standardized synthesis method to introduce nine metal promoters (0.5 wt.%) into In2O3. Methanol productivity generally increased on M‐In2O3 with selectivity following Pd ≈ Pt > Rh ≈ Ru ≈ Ir > Ni ≈ Co > Ag ≈ In2O3 > Au. In‐depth characterization, kinetic analyses, and theoretical calculations reveal a range of metal‐dependent speciation which dictate catalyst architecture and degree of promotion. Atomically‐dispersed promoters (Pd, Pt, Rh, Ru, and Ir) grant the highest improvement in performance, particularly Pd and Pt, which markedly promote hydrogen activation while hindering undesired CO formation. In contrast, metals in clustered (Ni and Co) and nanoparticle (Ag and Au) forms display moderate and no promotion, respectively. This study provides an atomic‐level understanding of In2O3 promotion based on a unified protocol, and highlights the potential of FSP to engineer complex catalytic systems toward more efficient energy transformations. [ABSTRACT FROM AUTHOR]

The article titled "Consumer Grade Polyethylene Recycling via Hydrogenolysis on Ultrafine Supported Ruthenium Nanoparticles" published in Angewandte Chemie discusses the development of catalysts for the chemical recycling of high-density polyethylene. The researchers, led by Javier Pérez-Ramírez, found that 1-nm ruthenium particles supported on titania can effectively catalyze the hydrogenolysis of plastic caps used in soft drinks, converting them into C1-C45 alkanes. The study also examines the impact of common additives on the catalytic process. The authors of the article are Shibashish D. Jaydev, Antonio J. Martín, Marc-Eduard Usteri, Katia Chikri, Henrik Eliasson, Rolf Erni, and Javier Pérez-Ramírez. [Extracted from the article]

The article titled "Back Cover: Consumer Grade Polyethylene Recycling via Hydrogenolysis on Ultrafine Supported Ruthenium Nanoparticles" discusses the development of catalysts for the chemical recycling of high-density polyethylene. The researchers, led by Javier Pérez-Ramírez, found that 1-nm ruthenium particles supported on titania can effectively catalyze the hydrogenolysis of plastic caps used in soft drinks, converting them into C1-C45 alkanes. The study also examines the impact of common additives on the catalytic process. The authors provide valuable insights into the mechanistic routes and deactivation pathways involved in the recycling process. [Extracted from the article]

[Display omitted] • Impregnated ZnO/ZrO 2 catalysts rival state-of-the-art benchmarks in CO 2 hydrogenation. • Stable methanol productivity > 0.7 g h−1 g cat −1 attained in CO 2 and CO 2 + CO feeds. • Tuning content to 5 mol% Zn on high-surface m -ZrO 2 support maximized Zn dispersion. • Facile vacancy generation and retention of isolated zinc sites during reaction. • Successful translation of performance and architecture from powder to technical form. While impregnation approaches are attractive, scalable routes for preparing supported oxide catalysts, achieving competitive methanol productivities over impregnated ZnO/ZrO 2 remains challenging as they underperform state-of-the art systems with isolated zinc sites. Herein, by targeting the optimal active site structure, ZnO/ZrO 2 systems prepared by impregnation achieve stable methanol space–time yields of 0.73 g MeOH h−1 g cat −1 during CO 2 and hybrid CO-CO 2 hydrogenation at suitable conditions. Notably, controlling the catalyst formulation using 5 mol% Zn and a high surface area m -ZrO 2 support fosters high zinc dispersion. In situ electron paramagnetic resonance and operando X-ray spectroscopy studies affirm the retention of isolated zinc species and facile generation of associated oxygen vacancies during the reaction. Analysis of pore structure and composition within the shaped bodies evidences abundant mesopores and a uniform zinc distribution, ensuring similar performance when translating from powder to technical forms. This work bridges fundamental understanding with practical demonstration of ZnO/ZrO 2 systems. [ABSTRACT FROM AUTHOR]

Catalysts based on individual precious metals on carbon‐ and oxide‐based carriers have shown remarkably selective behavior in the hydrodebromination of CH2Br2 to CH3Br, an important transformation within halogen‐mediated methane upgrading processes. However, the high susceptibility of the active phase to coking and to sintering, which cannot be overcome by controlling the nuclearity of the metal species, hinders their practical implementation. Herein, a platform of carbon‐supported Ir−Ru catalysts with distinct metal ratios at comparable metal nanoparticle size (ca. 1.0 nm) was adopted to systematically study the effects of a second metal on reactivity and stability. Catalytic tests reveal ruthenium‐doped iridium nanoparticles as the first system that combines high CH3Br selectivity (up to 93 %) with unprecedented stability, outperforming any of the previously reported catalysts. This superior performance was rationalized by the intimate interaction between the two metals, forming ruthenium‐poor surface alloys, which enable suppressing deactivation mechanisms as well as over hydrogenation/coking pathways. [ABSTRACT FROM AUTHOR]

[Display omitted] • Prins cyclisation from isovaleraldehyde and isoprenol to tetrahydropyranol. • Zeolites with varying acidity and hierarchical materials as catalysts. • H-Beta-300 zeolite giving 72% selectivity to the desired product at 99% conversion. • The cis/trans ratio of tetrahydropyranols depends on porous structure. • Parallel formation of tetrahydropyranol and dihydropyran confirmed by DFT. In this work, several heterogeneous micro- and mesoporous, acidic catalysts were tested for the selective synthesis of Florol®, an industrial product formed via condensation and rehydration starting from isoprenol and isovaleraldehyde in dimethylcarbonate as a solvent. The results showed that a mildly acidic, microporous H-Beta-300 with SiO 2 /Al 2 O 3 ratio of 300 was the best catalyst, giving 72% selectivity with 99% conversion at 40 °C when using the molar ratio isoprenol to isovaleraldehyde of 1:5. More acidic zeolites gave slightly lower selectivity, while the lowest selectivity (up to 52%) was obtained with mesoporous catalysts exhibiting mild acidity and no strong Brønsted acid sites. Selectivity to pyranols was nearly constant when changing temperature, while a larger excess of isovaleraldehyde promoted formation of tetrahydropyranol. H-Beta-300 catalyst was successfully after calcination at 400 °C. DFT calculations pointed out on the parallel formation of tetrahydro pyranols and dihydropyrans, which are the corresponding dehydration products. [ABSTRACT FROM AUTHOR]

[Display omitted] • Metal nanostructures on nitrogen-doped carbon studied in CH 2 X 2 hydrodehalogenation. • Nanoparticle-based systems provide the highest catalytic activity and stability. • Selectivity to the target CH 3 X depends on the active phase size and halogen type. • Ir single atoms compete with the best reported CH 2 Cl 2 hydrodechlorination catalysts. • Adsorption and dissociation energies of CH 2 X 2 and H 2 govern catalytic performance. Nanostructuring metal catalysts has been demonstrated as an attractive strategy to enable selective hydrodehalogenation of CH 2 X 2 (X = Cl, Br) to CH 3 X, but active phase size effects of promising metals and the role of the halogen are still poorly understood. Herein, the impact of these parameters on performance (activity, selectivity, and stability) is systematically assessed by employing a platform of N–doped carbon–supported metal nanostructures (Ir, Pt, Ru, and Ni), ranging from single atoms (SA) with defined coordination environment to nanoparticles (NP) of ca. 3.0 nm. Catalytic tests reveal that when compared to single atoms, highest reaction rates are attained over NP–based systems, which also exhibit improved stability ranking as Ir ≈ Pt > Ru ≫ Ni, independent of the halogen. The product distribution was markedly affected by the nanostructure and speciation of the active center as well as the dihalomethane type. Specifically, CH 3 Cl is the main reaction product over SA in hydrodechlorination, achieving an exceptional selectivity over Ir (up to 95%). In contrast, NP mainly generated CH 4 or coke. Comparable patterns were observed in hydrodebromination, except over Ru, which exhibited an inverse structure–selectivity trend. Density Functional Theory simulations shed light on the speciation of the active phase and identified the adsorption and dissociation energies of CH 2 X 2 and H 2 as descriptors for catalytic reactivity. These findings elucidate hydrodehalogenation performance patterns, highlighting the impact of nanostructuring and the halogen type to advance future catalyst design. [ABSTRACT FROM AUTHOR]

Nanostructuring earth‐abundant metals as single atoms or clusters of controlled size on suitable carriers opens new routes to develop high‐performing heterogeneous catalysts, but resolving speciation trends remains challenging. Here, we investigate the potential of low‐nuclearity iron catalysts in the continuous liquid‐phase semi‐hydrogenation of various alkynes. The activity depends on multiple factors, including the nuclearity and ligand sphere of the metal precursor and their evolution upon interaction with the mesoporous graphitic carbon nitride scaffold. Density functional theory predicts the favorable adsorption of the metal precursors on the scaffold without altering the nuclearity and preserving some ligands. Contrary to previous observations for palladium catalysts, single atoms of iron exhibit higher activity than larger clusters. Atomistic simulations suggest a central role of residual carbonyl species in permitting low‐energy paths over these isolated metal centers. [ABSTRACT FROM AUTHOR]

5-Methylfurfural (MF) is a critical commodity chemical used as food additive and synthetic intermediate. Opening a sustainable route towards highly selective synthesis of MF from 5-hydroxymethylfurfural (HMF) is of great significance, but has demonstrated extremely challenging. Herein, we report an efficient process for the selective production of MF from HMF over an anatase-supported gold catalyst (Au/a-TiO 2). During the hydrogenolysis of HMF, the desired C O bond is maintained and MF can be obtained in a high yield of 83.1 %, exhibiting excellent stability both in batch and flow operation. A combination of experimental and theoretical analyses attribute the superior performance of Au/a-TiO 2 to the synergistic effect of limited H access, low adsorption of reactants, and avoiding condensation, driven by the high concentration of oxygen vacancies in the support. This study highlights a novel approach of tailoring the coverage of active species for the selective transformation of renewable compounds into high-value-added chemicals. [Display omitted] • Selective production of MF from HMF via direct hydrogenolysis of the hydroxyl group using the Au/a-TiO 2 catalyst. • The C=O functional group was preserved under reductive conditions and MF can be obtained in a high yield of 83.1%. • The Au/a-TiO 2 catalyst shows high activity, remarkable selectivity, and excellent stability both in batch and flow operation. • The synergistic effect of limited H access, low adsorption of reactants, high concentration of oxygen vacancies. • This study paves the way for the design of new bifunctional catalysts toward selective hydrogenolysis of biomass. [ABSTRACT FROM AUTHOR]

Keywords: CO2-Hydrierung; Metall-Metalloxid-Wechselwirkungen; Methanolsynthese; Operando Analyse; Pd-In2O3/ZrO2 Katalysator DE CO2-Hydrierung Metall-Metalloxid-Wechselwirkungen Methanolsynthese Operando Analyse Pd-In2O3/ZrO2 Katalysator 1 1 1 10/12/23 20231016 NES 231016 B Developing scalable systems b and understanding dynamic behaviors are crucial for advancing the technological potential of multicomponent catalysts for CO SB 2 sb -based methanol synthesis. In their Research Article (e202306563), Javier Pérez-Ramírez and co-workers show that the reaction-induced restructuring of Pd-In SB 2 sb O SB 3 sb /ZrO SB 2 sb systems, prepared via impregnation, leads to a unique architecture that integrates the necessary acid-base functionality of In SB 2 sb O SB 3 sb with the H SB 2 sb splitting ability of an InPd SB 2 sb alloy, while also ensuring high stability. [Extracted from the article]

Developing scalable systems and understanding dynamic behaviors are crucial for advancing the technological potential of multicomponent catalysts for CO2‐based methanol synthesis. In their Research Article (e202306563), Javier Pérez‐Ramírez and co‐workers show that the reaction‐induced restructuring of Pd‐In2O3/ZrO2 systems, prepared via impregnation, leads to a unique architecture that integrates the necessary acid‐base functionality of In2O3 with the H2 splitting ability of an InPd2 alloy, while also ensuring high stability. [ABSTRACT FROM AUTHOR]

CO2 Hydrogenation, Metal-Metal Oxide Interactions, Methanol Synthesis, Operando Analysis, Pd-In2O3/ZrO2 Catalyst Inside Cover: Reaction-Induced Metal-Metal Oxide Interactions in Pd-In2O3/ZrO2 Catalysts Drive Selective and Stable CO2 Hydrogenation to Methanol (Angew. Keywords: CO2 Hydrogenation; Metal-Metal Oxide Interactions; Methanol Synthesis; Operando Analysis; Pd-In2O3/ZrO2 Catalyst EN CO2 Hydrogenation Metal-Metal Oxide Interactions Methanol Synthesis Operando Analysis Pd-In2O3/ZrO2 Catalyst 1 1 1 10/12/23 20231016 NES 231016 B Developing scalable systems b and understanding dynamic behaviors are crucial for advancing the technological potential of multicomponent catalysts for CO SB 2 sb -based methanol synthesis. [Extracted from the article]

Keywords: CO2 hydrogenation; flame spray pyrolysis; oxygen vacancies; sustainable methanol; ZnZrOx catalysts EN CO2 hydrogenation flame spray pyrolysis oxygen vacancies sustainable methanol ZnZrOx catalysts 1 1 1 04/17/23 20230413 NES 230413 B Methanol Synthesis b In article number 2204122, Javier Pérez-Ramírez and co-workers apply flame spray pyrolysis to design superior ZnZrO SB I x i sb catalysts for methanol synthesis from CO SB 2 sb . Design of Flame-Made ZnZrOx Catalysts for Sustainable Methanol Synthesis from CO2 (Adv. CO2 hydrogenation, flame spray pyrolysis, oxygen vacancies, sustainable methanol, ZnZrOx catalysts. [Extracted from the article]

Active site coordination, bimetallic systems, cooperativity effects, single-atom catalysts By selectively occupying the most energetically favorable cavities in the carbon host, Pt atoms drive Ru atoms to assume a distinct, more active configuration. Keywords: active site coordination; bimetallic systems; cooperativity effects; single-atom catalysts EN active site coordination bimetallic systems cooperativity effects single-atom catalysts 1 1 1 12/27/22 20221222 NES 221222 B Bimetallic Single Atom Catalysts b In article number 2206513, Javier Pérez-Ramírez, Núria López and co-workers investigate cooperativity mechanisms between fully isolated Ru and Pt atoms via the hydrogen evolution reaction, demonstrating that catalytic synergies can arise in the absence of direct metal-metal interactions. [Extracted from the article]

The conversion of wet waste (e.g., food waste, sewage sludge, and animal manure) into bioenergy is a promising strategy for sustainable energy generation and waste management. Although experimental efforts have driven waste conversion technologies (WCTs) to various degrees of maturity, computational modeling has equally contributed to this endeavor. This review focuses on the application of modeling techniques, including computational fluid dynamics (CFD), process simulation (PS), and machine learning (ML) on WCTs including anaerobic digestion, hydrothermal carbonization, gasification, pyrolysis and incineration. It addresses in a concise manner on how CFD models aid in understanding of the complex process and their molecular kinetics; while PS and ML models help in understanding the reaction kinetics, variable-response relationship, techno-economic assessment and sensitivity analysis. Relevant modeling approaches with their pros and cons are summarized and case studies are presented for each WCT. Moreover, a comparative evaluation among the three modeling techniques, along with their recent and ongoing developments are highlighted. Hybrid frameworks derived by combining mechanistic and ML models are proposed, which are expected to advance future wet waste valorization strategies for sustainable clean energy production and waste management. [ABSTRACT FROM AUTHOR]

Ammonia Oxidation, Au/CeO2, Metal-Support Interface, Nitrous Oxide, Reaction Mechanisms Keywords: Ammonia Oxidation; Au/CeO2; Metal-Support Interface; Nitrous Oxide; Reaction Mechanisms EN Ammonia Oxidation Au/CeO2 Metal-Support Interface Nitrous Oxide Reaction Mechanisms 1 1 1 04/27/22 20220502 NES 220502 B A game of two halves b Direct ammonia oxidation unlocks a pathway towards affordable and efficient production of nitrous oxide, a highly promising agent for selective oxidation reactions, but necessitates the development of suitable catalysts. Back Cover: Ceria-Supported Gold Nanoparticles as a Superior Catalyst for Nitrous Oxide Production via Ammonia Oxidation (Angew. [Extracted from the article]

Keywords: Ammonia Oxidation; Au/CeO2; Metal-Support Interface; Nitrous Oxide; Reaction Mechanisms EN Ammonia Oxidation Au/CeO2 Metal-Support Interface Nitrous Oxide Reaction Mechanisms 1 1 1 04/27/22 20220502 NES 220502 B Ein Spiel zweier Hälften b Die direkte Oxidation von Ammoniak eröffnet einen Weg zur kostengünstigen und effizienten Produktion von Stickstoffoxid, einem vielversprechenden Reagens für selektive Oxidationsreaktionen. Rücktitelbild: Ceria-Supported Gold Nanoparticles as a Superior Catalyst for Nitrous Oxide Production via Ammonia Oxidation (Angew. Ammonia Oxidation, Au/CeO2, Metal-Support Interface, Nitrous Oxide, Reaction Mechanisms. [Extracted from the article]

The development of efficient CO 2 conversion catalysts is a long-lasting desire. Herein, we introduce an atomic Pd-promoted ZnZrO x solid solution catalyst (Pd-ZnZrO x), which shows markedly enhanced rate of methanol production compared to bare ZnZrO x , as well as excellent stability over 100 h on stream. Up to 0.8 at% (i. e. 0.6 wt%), Pd can be atomically dispersed in ZnZrO x , leading to more oxygen vacancies on the mixed oxide that foster methanol production. Kinetic analysis and in situ DRIFTS reveal that hydrogen activation is limited on ZnZrO x , but Pd doping facilitates H 2 dissociation as well as the consequent formation of HCOO*, thus boosting CO 2 conversion to methanol. DFT analyses suggest that the presence of atomic Pd enables a more exothermic H 2 dissociation, which increases the availability of surface H and facilitates CO 2 hydrogenation on adjacent Zn sites, providing rationale on the high activity and robustness of Pd-ZnZrO x in CO 2 hydrogenation. [Display omitted] • Coprecipitation of Zn, Zr, and Pd precursors forms atomically dispersed Pd on ZnZrO x. • Atomic Pd-doping leads to higher concentration of surface oxygen vacancies. • Atomic Pd-promoted ZnZrO x shows excellent CO 2 hydrogenation activity and lifetime. • Pd promotes H 2 splitting and the stabilization of key intermediates for CH 3 OH. [ABSTRACT FROM AUTHOR]

CO 2 hydrogenation, green methanol, indium oxide, metal speciation, promotion Flame Spray Pyrolysis as a Synthesis Platform to Assess Metal Promotion in In2O3-Catalyzed CO2 Hydrogenation (Adv. Keywords: CO 2 hydrogenation; green methanol; indium oxide; metal speciation; promotion EN CO 2 hydrogenation green methanol indium oxide metal speciation promotion 1 1 1 04/18/22 20220414 NES 220414 B Flame Spray Pyrolysis b In article number 2103707, Núria López, Javier Pérez-Ramírez and co-workers apply flame spray pyrolysis as a standardized synthesis method to investigate promotional effects of nine transition metals in In SB 2 sb O SB 3 sb -catalyzed CO SB 2 sb hydrogenation to methanol, revealing that catalyst architecture (single atoms, clusters, and nanoparticles) and corresponding reactivity are dictated by the nature of the promoter. [Extracted from the article]

In their Communication, A. J. Saadun et al. study bimetallic systems of distinct composition and equivalent nanoparticle size, showing that the formation of dilute ruthenium alloys with iridium suppresses deactivating overhydrogenation or coking pathways observed on the respective monometallic systems. Bimetallic catalysts, hydrodebromination, iridium, nanoparticles, ruthenium Keywords: bimetallic catalysts; hydrodebromination; iridium; nanoparticles; ruthenium EN bimetallic catalysts hydrodebromination iridium nanoparticles ruthenium 1 1 1 01/25/22 20220121 NES 220121 B The Cover Feature b shows a bimetallic Ir-doped Ru nanoparticle supported on carbon with unprecedented selective and stable character in the hydrodebromination of dibromomethane to bromomethane. [Extracted from the article]

Alkyne hydrogenation, Iron catalysts, Nuclearity effects, Single atoms, Carbon nitride Cover Feature: Precursor Nuclearity and Ligand Effects in Atomically-Dispersed Heterogeneous Iron Catalysts for Alkyne Semi-Hydrogenation (ChemCatChem 14/2021) Keywords: Alkyne hydrogenation; Iron catalysts; Nuclearity effects; Single atoms; Carbon nitride EN Alkyne hydrogenation Iron catalysts Nuclearity effects Single atoms Carbon nitride 3199 3199 1 07/30/21 20210721 NES 210721 B The Cover Feature b depicts different single-atom species stabilized from iron pentacarbonyl on graphitic carbon nitride and their distinct selective hydrogenation activity (shown by the color of the light stream). [Extracted from the article]