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Articles by Sharon Mitchell
Toward Predictive Theory in Single-Atom Catalysis
1 Introduction Density functional theory (DFT) has become a key tool in heterogeneous catalysis for connecting atomic-scale structure with catalytic function [1-3]. Advances in computational approaches have progressively extended first-principles modeling from idealized extended surfaces [4] toward increasingly complex catalytic motifs, including supported metal clusters [5, 6] and single-atom catalysts (SAC) [7, 8], reflecting a growing ambition to describe complex catalytic phenomena [9].
Single atoms of indium on hafnia enable superior CO2-based methanol synthesis - Nature Nanotechnology Original
Abstract Indium–zirconium oxides rank among the most selective and stable catalysts for CO2 hydrogenation to methanol. Yet, despite extensive research, the mechanistic origin of the exceptional role of monoclinic zirconia remains unresolved and continues to set the benchmark in the field. Here we show that monoclinic hafnia, a wide-bandgap oxide rarely explored in catalysis, can outperform this benchmark.
Graded Calorie Restriction Causes Graded Slowing of Epigenetic Ageing in Mice
1 Introduction The global population aged 65+ years is growing at about 30 million per year, leading to major societal challenges (United Nations 2023). During ageing, molecular damage accumulates over time, leading to reduced homeostasis and increased susceptibility to age-related disease (Tenchov et al. 2024). Ageing is heterogeneous, complex, and multi-factorial (López-Otín et al. 2013).
Reproduction Has Immediate Effects on Female Mortality, but No Discernible Lasting Physiological Impacts: A Test of the Disposable Soma Theory
Keywords Animals, Female, Reproduction, Mice, Oxidative Stress, Mice, Inbred C57BL, Energy Metabolism, Body Composition, Longevity, Lactation, Mortality, aging, lifespan, reproduction Abstract The disposable soma theory (DST) posits that organisms age and die because of a direct trade-off in resource allocation between reproduction and somatic maintenance. DST predicts that investments in reproduction accentuate somatic damage which increase senescence and shortens lifespan.
Design Principles of Catalytic Materials for CO2 Hydrogenation to Methanol (Adv. Mater. 48/2024)
Thaylan Pinheiro Araújo Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1, Zurich, 8093 Switzerland Search for more papers by this author
Design Principles of Catalytic Materials for CO2 Hydrogenation to Methanol
1 Introduction With a global production of ≈110 Mt per year, methanol is crucial for manufacturing numerous other chemicals and is a prospective fuel for the maritime shipping industry.[1-3] Driven by the latter, the demand for methanol will increase dramatically, with estimates reaching ≈360–500 Mt per year by 2050.[3, 4] However, current methanol production relies heavily on fossil feedstocks, necessitating a shift toward carbon-neutral routes to effectively meet this growth while...
The need to integrate mass- and energy-based metrics with life cycle impacts for sustainable chemicals manufacture
The need to integrate mass- and energy-based metrics with life cycle impacts for sustainable chemicals manufacture† Effective use of quantitative metrics is fundamental to guiding innovation toward more sustainable chemicals. At present, metrics employed in Green Chemistry, such as the E-factor, Process Mass Intensity, or Energy Intensity, focus on mass or energy efficiency at specific levels – reaction, process, or plant.
Back Cover: The Future of Chemical Sciences is Sustainable (Angew. Chem. Int. Ed. 26/2024)
Graphical Abstract 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.
Low-nuclearity CuZn ensembles on ZnZrOx catalyze methanol synthesis from CO2 - Nature Communications
Abstract Metal promotion could unlock high performance in zinc-zirconium catalysts, ZnZrOx, for CO2 hydrogenation to methanol. Still, with most efforts devoted to costly palladium, the optimal metal choice and necessary atomic-level architecture remain unclear. Herein, we investigate the promotion of ZnZrOx catalysts with small amounts (0.5 mol%) of diverse hydrogenation metals (Re, Co, Au, Ni, Rh, Ag, Ir, Ru, Pt, Pd, and Cu) prepared via a standardized flame spray pyrolysis approach.
The Future of Chemical Sciences is Sustainable
1 Introduction For decades, researchers in chemical sciences have played a pivotal role in shaping our world through their creative pursuit of novel molecules and materials.
Taxonomy of teaching methods and their use in health professions education: a scoping review protocol
Methods and analysis This scoping review follows the review frameworks for methodological guidance for conducting a Joanna Briggs Institute (JBI) scoping review,34 35 aligned to Arksey & O’Malley’s framework32 and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR)36 ,37 (online supplemental file 1).
Language models and protocol standardization guidelines for accelerating synthesis planning in heterogeneous catalysis - Nature Communications
Abstract Synthesis protocol exploration is paramount in catalyst discovery, yet keeping pace with rapid literature advances is increasingly time intensive. Automated synthesis protocol analysis is attractive for swiftly identifying opportunities and informing predictive models, however such applications in heterogeneous catalysis remain limited.
Advances in heterogeneous single-cluster catalysis - Nature Reviews Chemistry
Abstract Heterogeneous single-cluster catalysts (SCCs) comprising atomically precise and isolated metal clusters stabilized on appropriately chosen supports offer exciting prospects for enabling novel chemical reactions owing to their broad structural diversity with unparalled opportunities for engineering their properties.
Automated Image Analysis for Single-Atom Detection in Catalytic Materials by Transmission Electron Microscopy
Single-atom catalytic sites may have existed in all supported transition metal catalysts since their first application. Yet, interest in the design of single-atom heterogeneous catalysts (SACs) only really grew when advances in transmission electron microscopy (TEM) permitted direct confirmation of metal site isolation.
Carbon‐Supported Bimetallic Ruthenium‐Iridium Catalysts for Selective and Stable Hydrodebromination of Dibromomethane
Abstract Bimetallic Nanoparticles: The hydrodebromination of CH2Br2 to CH3Br over benchmark monometallic catalysts still presents major challenges related to catalyst stability. Herein, the highly selective and stable performance of bimetallic ruthenium-doped iridium catalysts on carbon is demonstrated. This unprecedented performance is attributed to the formation of ruthenium-poor surface alloys, which ultimately limit undesired pathways leading to CH4/coke generation.
The effects of graded calorie restriction XVII: Multitissue metabolomics reveals synthesis of carnitine and NAD, and tRNA charging as key pathways
You May Also be Interested in Even after atmospheric microplastics settle on land or in water, they may reenter the atmosphere, a study suggests. Image credit: Janice Brahney. A study examines how humans have reshaped terrestrial nature and suggests that restoring Indigenous peoples and local communities to positions of environmental stewardship may help conserve biodiversity. Image credit: Erle C. Ellis.
Very-low-protein diets lead to reduced food intake and weight loss, linked to inhibition of hypothalamic mTOR signaling, in mice
Main text (Cell Metabolism 33, 888–904.e1–e6; May 4, 2021) In the original version of the article’s Figure 7, the Figures 7P and 7O are the same. We mistakenly duplicated the figure 7P during the production process. This error has been corrected online. As this error occurred in figure production and not during data analysis, this error has no impact on the main results or conclusions of this publication. The authors apologize for this error and any confusion it may have caused. Figure 7.
Nanoscale engineering of catalytic materials for sustainable technologies
Abstract Nanostructured materials of diverse architecture are ubiquitous in industrial catalysis. They offer exciting prospects to tackle various sustainability challenges faced by society. Since the introduction of the concept a century ago, researchers aspire to control the chemical identity, local environment and electronic properties of active sites on catalytic surfaces to optimize their reactivity in given applications.
The effects of graded levels of calorie restriction: V. Impact of short term calorie and protein restriction on physical activity in the C57BL/6 mouse
1. Turturro A, Duffy P, Hass B, Kodell R, Hart R. Survival characteristics and age-adjusted disease incidences in C57BL/6 mice fed a commonly used cereal-based diet modulated by dietary restriction. The Journals of Gerontology Series A: Biological Sciences and Medical Sciences. 2002;57:B379–B389. [PubMed] [Google Scholar] 2. Fontana L, Partridge L, Longo VD. Extending healthy life span—from yeast to humans. Science. 2010;328:321–326. [PMC free article] [PubMed] [Google Scholar] 3. Speakman JR, Mitchell SE.
Substrate substitution effects in the Fries rearrangement of aryl esters over zeolite catalysts
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The effects of graded levels of calorie restriction: VI. Impact of short-term graded calorie restriction on transcriptomic responses of the hypothalamic hunger and circadian signaling pathways
1. Mercken EM, Crosby SD, Lamming DW, Jebailey L, Krzysik-Walker S, Villareal DT, Capri M, Franceschi C, Zhang Y, Becker K, Sabatini DM, de Cabo R, Fontana L. Calorie restriction in humans inhibits the PI3K/AKT pathway and induces a younger transcription profile. Aging Cell. 2013;12:645–651. [PMC free article] [PubMed] [Google Scholar] 2. Fontana L, Meyer TE, Klein S, Holloszy JO. Long-term calorie restriction is highly effective in reducing the risk for atherosclerosis in humans.
Dual catalyst system for selective vinyl chloride production via ethene oxychlorination
Dual catalyst system for selective vinyl chloride production via ethene oxychlorination† Matthias Scharfe,a Vladimir Paunović, a Sharon Mitchell, a Roland Hauert,b Shibo Xi,c Armando Borgna c and Javier Pérez-Ramírez *a Author affiliations * Corresponding authors a Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog Weg 1, 8093 Zurich, Switzerland E-mail: jpr@chem.ethz.ch b EMPA, Swiss Federal Laboratories for Materials...
Dual catalyst system for selective vinyl chloride production via ethene oxychlorination
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Controlling the speciation and reactivity of carbon-supported gold nanostructures for catalysed acetylene hydrochlorination
Carbon-supported gold catalysts have the potential to replace the toxic mercuric chloride-based system applied industrially for acetylene hydrochlorination, a key technology for the manufacture of polyvinyl chloride. However, the design of an optimal catalyst is essentially hindered by the difficulties in assessing the nature of the active site.
Reactivity of Single‐Atom Heterogeneous Catalysts: Unique and Multifaceted
Single‐atom heterogeneous catalysts (SACs) attached to carefully chosen hosts, are attracting considerable interest, principally because they offer maximal reactivity per metal atom and are usually readily recyclable. But the diminution of the atomic population of nanoparticles or nanoclusters to single atoms can significantly alter reactivity owing to consequent changes in the active site structure.
Reactivity of Single‐Atom Heterogeneous Catalysts: Unique and Multifaceted
Single‐atom heterogeneous catalysts (SACs) attached to carefully chosen hosts, are attracting considerable interest, principally because they offer maximal reactivity per metal atom and are usually readily recyclable. But the diminution of the atomic population of nanoparticles or nanoclusters to single atoms can significantly alter reactivity owing to consequent changes in the active site structure.
A heterogeneous single-atom palladium catalyst surpassing homogeneous systems for Suzuki coupling
Palladium-catalysed cross-coupling reactions, central tools in fine-chemical synthesis, predominantly employ soluble metal complexes despite recognized challenges with product purification and catalyst reusability1,2,3. Attempts to tether these homogeneous catalysts on insoluble carriers have been thwarted by suboptimal stability, which leads to a progressively worsening performance due to metal leaching or clustering4.
A harmonised European training syllabus for thoracic surgery: report from the ESTS/ERS task force group
As has been reported for respiratory medicine, a high variance exists among European countries in the content and modes of delivery for specialty training in thoracic surgery.
Doctors on the move: a European case study on the key characteristics of national recertification systems
Increased mobility of health professionals can pose potential threats to the quality of care. Suppose, for instance, a high performing, Romanian doctor moves to the Netherlands. There, this person will face a new work environment in a distinct healthcare system with specific quality guidelines and different morbidity patterns, and patient demands.
Update of the ERS international Adult Respiratory Medicine syllabus for postgraduate training
AbstractFirst published in 2006, the first European core syllabus in Adult Respiratory Medicine was developed with the intention of harmonising education and training throughout Europe.
Catalysis Science & Technology
S. Mitchell, J. M. Thomas and J. Pérez-Ramírez, Catal. Sci. Technol., 2017, Advance Article , DOI: 10.1039/C7CY90090B If you are not the author of this article and you wish to reproduce material from it in a third party non-RSC publication you must formally request permission using RightsLink. Go to our Instructions for using RightsLink page for details.
Tailoring the framework composition of carbon nitride to improve the catalytic efficiency of the stabilised palladium atoms
Graphitic carbon nitride (g-C3N4) exhibits unique properties for the preparation of single-atom heterogeneous catalysts (SAHCs) due to the presence of sixfold nitrogen-based coordination sites in the lattice. Despite the potential to profoundly affect the metal stabilisation and resulting catalytic properties, no work has previously investigated the effect of modifying the carrier composition. Here, we study the impact of doping carbon in g-C3N4 on the interaction with palladium.
Design of a technical Mg-Al mixed oxide catalyst for the continuous manufacture of glycerol carbonate
The availability of a heterogeneous catalyst, which contains cheap and abundant elements, has a scalable synthesis, is highly active and stable, retains its performance upon shaping into a technical form and can be operated in continuous mode, would pave the way for a more ecological and economical production of glycerol carbonate from glycerol and urea. Here, we show that a mixed oxide of Mg and Al is a promising active phase for this reaction.
Engineering of ZSM-5 zeolite crystals for enhanced lifetime in the production of light olefins via 2-methyl-2-butene cracking
The selective cracking of low-value C5 olefins such as 2-methyl-2-butene (2M2B), a growing by-product of deep catalytic cracking, over ZSM-5 zeolites is an attractive route for the on-purpose production of ethylene and propylene. Yet, several aspects, including the deactivation behaviour and the effect of the crystal properties (i.e., the size, morphology, amount of defects, and mesoporosity) on the performance, still lack understanding.
Engineering of ZSM-5 zeolite crystals for enhanced lifetime in the production of light olefins via 2-methyl-2-butene cracking
The selective cracking of low-value C5 olefins as 2-methyl-2-butene (2M2B), a growing by-product of deep catalytic cracking, over ZSM-5 zeolites is an attractive route for the on-purpose production of ethylene and propylene. Yet several aspects, including the deactivation behaviour and the effect of the crystal properties (i.e., the size, morphology, amount of defects, and mesoporosity) on the performance, still lack understanding.
Interfacial acidity in ligand-modified ruthenium nanoparticles boosts the hydrogenation of levulinic acid to gamma-valerolactone
Gamma-valerolactone (GVL), a versatile renewable compound listed among the top 10 most promising platform chemicals by the US Department of Energy, is produced via hydrogenation of levulinic acid (LA). The traditional high-loading ruthenium-on-carbon catalyst (5 wt% Ru) employed for this transformation suffers from low metal utilisation and poor resistance to deactivation due to the formation of RuO species.
Interfacial acidity in ligand-modified ruthenium nanoparticles boosts the performance for the continuous hydrogenation of levulinic acid to gamma-valerolactone - Green Chemistry (RSC Publishing)
Gamma-valerolactone (GVL), a versatile renewable compound listed among the top 10 most promising platform chemical by the US Department of Energy, is produced via hydrogenation of levulinic acid (LA). The traditional high-loading ruthenium-on-carbon catalyst (5 wt.% Ru) employed for this transformation suffers from low metal utilisation and poor resistance to deactivation due to the formation of RuOx species.
Ligand ordering determines the catalytic response of hybrid palladium nanoparticles in hydrogenation
Supported palladium nanoparticles, prepared by reducing the active metal in the presence of the hexadecyl(2-hydroxyethyl)dimethylammonium dihydrogen-phosphate (HHDMA) ligand and depositing the resulting colloids on titanium silicate (TiSi O ), represent a proven alternative to the archetypal poisoned catalysts in industrially-relevant selective hydrogenations.
Ligand ordering determines the catalytic response of hybrid palladium nanoparticles in hydrogenation
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