24 Result(s)
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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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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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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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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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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...
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Open AccessStability of heterogeneous single-atom catalysts: a scaling law map** thermodynamics to kinetics
Heterogeneous single-atom catalysts (SACs) hold the promise of combining high catalytic performance with maximum utilization of often precious metals. We extend the current thermodynamic view of SAC stability ...
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Open AccessInfrared spectroscopy data- and physics-driven machine learning for characterizing surface microstructure of complex materials
There is a need to characterize complex materials and their dynamics under reaction conditions to accelerate materials design. Adsorbate vibrational excitations are selective to adsorbate/surface interactions ...
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Open AccessScaling relationships and theory for vibrational frequencies of adsorbates on transition metal surfaces
Adsorbate vibrational excitations are an important fingerprint of molecule/surface interactions, affecting temperature contributions to the free energy and impacting reaction rate and equilibrium constants. Fu...
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Open AccessDurable and self-hydrating tungsten carbide-based composite polymer electrolyte membrane fuel cells
Proton conductivity of the polymer electrolyte membranes in fuel cells dictates their performance and requires sufficient water management. Here, we report a simple, scalable method to produce well-dispersed t...
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Open AccessNickel supported on nitrogen-doped carbon nanotubes as hydrogen oxidation reaction catalyst in alkaline electrolyte
The development of a low-cost, high-performance platinum-group-metal-free hydroxide exchange membrane fuel cell is hindered by the lack of a hydrogen oxidation reaction catalyst at the anode. Here we report th...
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Open AccessPatched bimetallic surfaces are active catalysts for ammonia decomposition
Ammonia decomposition is often used as an archetypical reaction for predicting new catalytic materials and understanding the very reason of why some reactions are sensitive on material’s structure. Core–shell ...
