Ewoud

Paired electrocatalysis enables the simultaneous production of value-added products through complementary cathodic and anodic reactions. Biomass-derived compounds can serve as versatile feedstocks to yield various valuable chemicals. Optimizing electrocatalysts, cell configurations, and processes is crucial for advancing the industrial-scale applications of biomass valorization through paired electrocatalysis.

Abstract

Electrochemical valorization of biomass represents an emerging research frontier, capitalizing on renewable feedstocks to mitigate carbon emissions. Traditional electrochemical approaches often suffer from energy inefficiencies due to the requirement of a second electrochemical conversion at the counter electrode which might generate non-value-added byproducts. This review article presents the advancement of paired electrocatalysis as an alternative strategy, wherein both half-reactions in an electrochemical cell are harnessed to concurrently produce value-added chemicals from biomass-derived feedstocks, potentially doubling the Faradaic efficiency of the whole process. The operational principles and advantages of different cell configurations, including 1-compartment undivided cells, H-type cells, and flow cells, in the context of paired electrolysis are introduced and compared, followed by the analysis of various catalytic strategies, from catalyst-free systems to sophisticated homogeneous and heterogeneous electrocatalysts, tailored for optimized performance. Key substrates, such as CO₂, 5-hydroxymethylfurfural (HMF), furfural, glycerol, and lignin are highlighted to demonstrate the versatility and efficacy of paired electrocatalysis. This work aims to provide a clear understanding of why and how both cathode and anode reactions can be effectively utilized in electrocatalytic biomass valorization leading to innovative industrial scalability.

Nature, Published online: 27 November 2024; doi:10.1038/d41586-024-03829-w

Alongside secret Santas and seasonal parties, many laboratories develop traditions to show appreciation to colleagues — from sweets and mulled wine to quizzes and ice-skating trips.

Nature, Published online: 21 November 2024; doi:10.1038/d41586-024-03784-6

Researchers say the social-media platform — an alternative to X — offers more control over the content they see and the people they engage with.

Nature, Published online: 19 November 2024; doi:10.1038/d41586-024-03746-y

The largest scholarly search engine is celebrating its 20th birthday, but AI-driven competitors offer advantages.

The purpose of this concept article is to unravel insights into the creative approaches in lignin-assisted photochemical reactions, focusing on photopolymerization to construct functional polymeric materials and photoreduction to provide valuable chemicals, wherein lignin serves as a macromolecular photoinitiator and a reductive photocatalyst, respectively.

Abstract

Lignin, the most abundant aromatic biopolymer, is emerging as a mainstay of the upcoming revolution in sustainable materials processing. Despite the inherent challenges associated with the heterogeneous structure of lignin, significant progress has recently been made in developing innovative strategies to valorize this fascinating aromatic biopolymer to deliver industry-demanded products via photoreactions. The purpose of this concept article is to unravel insights into these creative approaches in lignin-assisted photoreactions, focusing on photopolymerization to construct functional polymeric materials and photoreduction to provide valuable chemicals, wherein lignin serves as a macromolecular photoinitiator and a reductive photocatalyst, respectively. The existing strategies for improving the photochemical quantum yield of lignin in photopolymerization and harnessing lignin macromolecules as photoresponsive polymers to facilitate electron transfer in photocatalytic reactions are also summarized. In the future, such photochemical lignin valorization concepts could potentially provide new possibilities for achieving a profitable value chain for integrated biorefinery processes.

Nature, Published online: 18 November 2024; doi:10.1038/d41586-024-03761-z

From demonstrating technical prowess to setting out future ambitions, learn how to beat rival candidates and land your dream job.

Synlett
DOI: 10.1055/s-0043-1773495

Herein, we report that orthoformate ester and N,N-dimethylformamide di-tert-butyl acetal can be a source of alkoxy radicals. We have developed a coupling reaction with aryl halides as a way of utilizing them. This has led to the synthesis of aromatic ethers with tertiary alkoxy groups, which are generally considered difficult to synthesize.
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Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany

Article in Thieme eJournals:
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Nature, Published online: 13 November 2024; doi:10.1038/d41586-024-03676-9

Artificial intelligence could help speedily summarize research. But it comes with risks.

Polyester plastics have become an increasingly serious ecological problem worldwide after being discarded. Compared with incineration and landfill disposal methods, emerging technologies for recycling and upcycling plastics have attracted more attention. This review summarizes the recent research progress on traditional recycling methods and emerging upcycling strategies into monomers, value-added chemicals, fuels, etc.

Abstract

Polyester waste in the environment threatens public health and environmental ecosystems. Chemical recycling of polyester waste offers a dual solution to ensure resource sustainability and ecological restoration. This minireview highlights the traditional recycling methods and novel recycling strategies of polyester plastics. The conventional strategy includes pyrolysis, carbonation, and solvolysis of polyesters for degradation and recycling. Furthermore, the review delves into exploring emerging technologies including hydrogenolysis, electrocatalysis, photothermal, photoreforming, and enzymatic for upcycling polyesters. It emphasizes the selectivity of products during the polyester conversion process and elucidates conversion pathways. More importantly, the separation and purification of the products, the life cycle assessment, and the economic analysis of the overall recycling process are essential for evaluating the environmental and economic viability of chemical recycling of waste polyester plastics. Finally, the review offers perspective into the future challenges and developments of chemical recycling in the polyester economy.

Nature, Published online: 07 November 2024; doi:10.1038/d41586-024-03657-y

Deciphering how mammals respond to sensations through their fur could inspire further research on skin sensitivity.

Nature, Published online: 06 November 2024; doi:10.1038/d41586-024-03587-9

When research on an intriguing material called for hundreds of samples, secondary-school students, teachers and technicians stepped up.

Synlett
DOI: 10.1055/a-2422-0992

Mechanochemistry, a solvent-free approach that harnesses mechanical energy, is emerging as a transformative technique in modern chemistry. It has emerged from a niche technique to a versatile tool with broad applications. By inducing physical and chemical transformations, it enables the synthesis of complex molecules and nanostructured materials. Recent advancements have extended its applications beyond simple physical transformations to encompass catalytic processes, unlocking new possibilities for selective synthesis and product design. This account delves into the fundamentals of mechanochemistry and its applications in organic synthesis, also beyond traditional synthetic routes. Mechanochemistry offers new avenues for molecular and materials discovery, expanding the scope of accessible chemical space.1 Introduction2 Organic Synthesis in Ball Mills3 Combination with Different Energy Sources4 Advantages of Mechanochemistry5 Future of Mechanochemistry6 Conclusion
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Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany

Article in Thieme eJournals:
Table of contents  |  Abstract  |  Full text

Abstract

Biomass has been identified as the ultimate sustainable resource for all carbon-based consumer products of the chemical industries in the future. Its catalytic conversion leads to the formation of various platform chemicals that could partially or even fully replace the fossil-based building blocks that have been currently used in synthetic chemical processes. Among these compounds, levulinic acid (LA) has been recognized as a member of the “Top Value Added Chemicals from Biomass” and has attracted significant attention since the seminal paper reported by Werpy and Petersen in 2004. This review summarizes the properties, recent advances, and developments in the chemistry of levulinic acid. The production of LA from both plant and animal-based carbohydrate feedstocks via 5-hydroxymethylfurfural or furfuryl alcohol is discussed from a mechanistic perspective, highlighting intrinsic molecular-level limitations to LA formation. The efficiencies of recently developed catalytic systems are also summarized and compared. Furthermore, the conversion of LA into high-value-added downstream chemicals, including its role in the synthesis of complex molecular structures, is overviewed. This section discussed the reactions of LA in the points of view of its various transformations on carbonyl-, carboxy-, methyl-, and methylene functional groups. The reactions of these functionalities with C−, N−, O−, and S-nucleophiles, alcohols, amines, organometallic reagents, oxygen etc. were thematically summarized. Our review also outlooks to highlight the challenges and opportunities associated with the extensive research area of organic chemistry of levulinic acid.

Nature Catalysis, Published online: 23 October 2024; doi:10.1038/s41929-024-01226-0

Typically, active acyl intermediates are quenched with nucleophiles to complete carbonylation. Now, a visible-light-induced radical relay enables CO insertion and selective (hetero)aryl group migration without nucleophiles.

Light interacts with gas bubbles in various ways, potentially leading to photon losses in gas-liquid photochemical applications. Given that light is a costly 'reagent', understanding these losses is crucial for optimizing reactor efficiency. In this study, we address the challenge of quantifying these interactions by implementing a method that separately determines the photon flux and utilizes the effective optical path length as a key descriptor of photon absorption. The results reveal an unexpected impact of gas phase introduction in continuous-flow photoreactors. Notably, photon absorption, and consequently the throughput of a photoreactor, can be increased by the introduction of a gas phase. This enhancement arises from the reflection and refraction effects of gas bubbles, which can intensify light intensity in the liquid volume and thereby offset any loss in residence time. The photon absorption losses that were observed were associated with large bubbles and were less significant than anticipated. In contrast, the introduction of small bubbles was found to increase photon absorption, suggesting a potential strategy to optimize photoreactor performance.