46 Result(s)
within
Dionisios G. Vlachos
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Article
Open AccessRecycling polyolefin plastic waste at short contact times via rapid joule heating
The chemical deconstruction of polyolefins to fuels, lubricants, and waxes offers a promising strategy for mitigating their accumulation in landfills and the environment. Yet, achieving true recyclability of p...
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A US perspective on closing the carbon cycle to defossilize difficult-to-electrify segments of our economy
Electrification to reduce or eliminate greenhouse gas emissions is essential to mitigate climate change. However, a substantial portion of our manufacturing and transportation infrastructure will be difficult ...
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Progress and roadmap for electro-privileged transformations of bio-derived molecules
Biomass incorporates carbon captured from the atmosphere and can serve as a renewable feedstock for producing valuable chemicals and fuels. Here we look at how electrochemical approaches can impact biomass val...
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Open AccessNon-Oxidative Ethane Dehydrogenation in a Packed-Bed DBD Plasma Reactor
Plasma-assisted conversion of ethane (C2H6) can produce value-added chemical building blocks using green electricity. Here we employ a simple packed-bed coaxial dielectric barrier discharge (DBD) reactor to conve...
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Open AccessTemperature-dependent complex dielectric permittivity: a simple measurement strategy for liquid-phase samples
Microwaves (MWs) are an emerging technology for intensified and electrified chemical manufacturing. MW heating is intimately linked to a material’s dielectric permittivity. These properties are highly dependen...
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Open AccessHighly active, ultra-low loading single-atom iron catalysts for catalytic transfer hydrogenation
Highly effective and selective noble metal-free catalysts attract significant attention. Here, a single-atom iron catalyst is fabricated by saturated adsorption of trace iron onto zeolitic imidazolate framewor...
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Open AccessA two-stage strategy for upcycling chlorine-contaminated plastic waste
Chemical upcycling of polyolefin plastic waste to lubricant, wax and fuel-range hydrocarbons over metal-based catalysts is a crucial technological solution to the enormous environmental threat posed by plastic...
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Open AccessInsights into solvent and surface charge effects on Volmer step kinetics on Pt (111)
The mechanism of pH-dependent hydrogen oxidation and evolution kinetics is still a matter of significant debate. To make progress, we study the Volmer step kinetics on platinum (111) using classical molecular ...
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Open AccessTuning the reactivity of carbon surfaces with oxygen-containing functional groups
Oxygen-containing carbons are promising supports and metal-free catalysts for many reactions. However, distinguishing the role of various oxygen functional groups and quantifying and tuning each functionality ...
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Open AccessDeducing subnanometer cluster size and shape distributions of heterogeneous supported catalysts
Infrared (IR) spectra of adsorbate vibrational modes are sensitive to adsorbate/metal interactions, accurate, and easily obtainable in-situ or operando. While they are the gold standards for characterizing sin...
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Open AccessSelective hydrogenation via precise hydrogen bond interactions on catalytic scaffolds
The active site environment in enzymes has been known to affect catalyst performance through weak interactions with a substrate, but precise synthetic control of enzyme inspired heterogeneous catalysts remains...
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Open AccessElectronic modulation of metal-support interactions improves polypropylene hydrogenolysis over ruthenium catalysts
Ruthenium (Ru) is the one of the most promising catalysts for polyolefin hydrogenolysis. Its performance varies widely with the support, but the reasons remain unknown. Here, we introduce a simple synthetic st...
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Bifunctional hydroformylation on heterogeneous Rh-WOx pair site catalysts
Metal-catalysed reactions are often hypothesized to proceed on bifunctional active sites, whereby colocalized reactive species facilitate distinct elementary steps in a catalytic cycle1–8. Bifunctional active sit...
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Open AccessLigninGraphs: lignin structure determination with multiscale graph modeling
Lignin is an aromatic biopolymer found in ubiquitous sources of woody biomass. Designing and optimizing lignin valorization processes requires a fundamental understanding of lignin structures. Experimental cha...
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Tuning at the subnanometre scale
Supported subnanometre catalysts are atom efficient and possess unique properties, but their structure–activity relations are not well understood. Now it is possible to reveal their structure sensitivity by co...
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Programmable heating and quenching for efficient thermochemical synthesis
Conventional thermochemical syntheses by continuous heating under near-equilibrium conditions face critical challenges in improving the synthesis rate, selectivity, catalyst stability and energy efficiency, ow...
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Open AccessAutomated exploitation of the big configuration space of large adsorbates on transition metals reveals chemistry feasibility
Mechanistic understanding of large molecule conversion and the discovery of suitable heterogeneous catalysts have been lagging due to the combinatorial inventory of intermediates and the inability of humans to...
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Modulating the dynamics of Brønsted acid sites on PtWOx inverse catalyst
Brønsted acid sites on the oxide overlayers of metal–metal oxide inverse catalysts are often hypothesized to drive selective C–O bond activation. However, the Brønsted acid site nature and dynamics under worki...
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Open AccessReal-time dynamics and structures of supported subnanometer catalysts via multiscale simulations
Understanding the performance of subnanometer catalysts and how catalyst treatment and exposure to spectroscopic probe molecules change the structure requires accurate structure determination under working con...
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Open AccessRegularized machine learning on molecular graph model explains systematic error in DFT enthalpies
A major goal of materials research is the discovery of novel and efficient heterogeneous catalysts for various chemical processes. In such studies, the candidate catalyst material is modeled using tens to thou...
