Oxidation processes and me

Water Research, Journal Year: 2024, Volume and Issue: 253, P. 121148 - 121148

Published: Jan. 16, 2024

This publication summarizes my journey in the field of chemical oxidation processes for water treatment over last 30+ years. Initially, efficiency application oxidants micropollutant abatement was assessed by target compounds only. is controlled reaction kinetics and therefore, second-order rate constant these reactions are pre-requisite to assess feasibility such processes. Due tremendous efforts this area, we currently have a good experimental data base constants many oxidants, including radicals. Based on this, predictions can be made without with Quantitative Structure Activity Relationships Hammet/Taft or energies highest occupied molecular orbitals from quantum computations. Chemical has economically feasible extent transformation micropollutants often limited mineralization cannot achieved under realistic conditions. The formation products oxidant inherent following questions evolved years: Are formed biologically less active than compounds? Is there new toxicity associated products? more biodegradable corresponding In addition positive effects quality related micropollutants, react mainly matrix components as dissolved organic matter (DOM), bromide iodide. As fact, fraction consumed DOM typically > 99%, which makes inherently inefficient. consequences loss capacity inorganic disinfection byproducts also involving iodide, oxidized reactive bromine iodine their ensuing DOM. Overall, it turned out three decades, that complex understand manage. However, research led understanding underlying allow widespread optimized practice drinking water, municipal industrial wastewater reuse systems.

Language: Английский

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A human-machine interface for automatic exploration of chemical reaction networks

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: May 1, 2024

Abstract Autonomous reaction network exploration algorithms offer a systematic approach to explore mechanisms of complex chemical processes. However, the resulting networks are so vast that an all potentially accessible intermediates is computationally too demanding. This renders brute-force explorations unfeasible, while with completely pre-defined or hard-wired constraints, such as element-specific coordination numbers, not flexible enough for systems. Here, we introduce STEERING WHEEL guide otherwise unbiased automated exploration. The algorithm intuitive, generally applicable, and enables one focus on specific regions emerging network. It also allows guiding data generation in context mechanism exploration, catalyst design, other optimization challenges. demonstrated elucidation transition metal catalysts. We highlight how catalytic cycles reproducible way. objectives fully adjustable, allowing harness both structure-specific (accurate) calculations well broad high-throughput screening possible intermediates.

Language: Английский

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SCINE—Software for chemical interaction networks

The Journal of Chemical Physics, Journal Year: 2024, Volume and Issue: 160(22)

Published: June 10, 2024

The software for chemical interaction networks (SCINE) project aims at pushing the frontier of quantum calculations on molecular structures to a new level. While individual as well simple relations between them have become routine in chemistry, developments pushed field high-throughput calculations. Chemical may be created by search specific properties design attempt, or they can defined set elementary reaction steps that form network. modules SCINE been designed facilitate such studies. features are (i) general applicability applied methodologies ranging from electronic structure (no restriction elements periodic table) microkinetic modeling (with little restrictions molecularity), full modularity so also stand-alone programs exchanged external packages fulfill similar purpose (to increase options computational campaigns and provide alternatives case tasks hard impossible accomplish with certain programs), (ii) high stability autonomous operations control steering an operator easy possible, (iii) embedding into complex heterogeneous environments taken individually context A graphical user interface unites all ensures interoperability. All components made available open source free charge.

Language: Английский

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Multi-Time-Scale Simulation of Complex Reactive Mixtures: How Do Polyoxometalates Form?

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(34), P. 18920 - 18930

Published: July 27, 2023

Understanding the dynamics of reactive mixtures still challenges both experiments and theory. A relevant example can be found in chemistry molecular metal-oxide nanoclusters, also known as polyoxometalates. The high number species potentially involved, interconnectivity reaction network, precise control pH concentrations needed synthesis such make theoretical/computational treatment processes cumbersome. This work addresses this issue relying on a unique combination recently developed computational methods that tackle construction, kinetic simulation, analysis complex chemical networks. By using Bell-Evans-Polanyi approximation for estimating activation energies, an accurate robust linear scaling correcting computed pKa values, we report herein multi-time-scale simulations self-assembly polyoxotungstates comprise 22 orders magnitude, from tens femtoseconds to months time. very large time span was required reproduce fast acid/base equilibria (at 10-12 s), relatively slow reactions formation key clusters metatungstate 103 assembly decatungstate 106 s). Analysis data network topology shed light onto details main mechanisms, which explains origin thermodynamic followed by reaction. Simulations at alkaline fully experimental evidence since do not form under those conditions.

Language: Английский

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Deep reaction network exploration of glucose pyrolysis

Proceedings of the National Academy of Sciences, Journal Year: 2023, Volume and Issue: 120(34)

Published: Aug. 14, 2023

Resolving the reaction networks associated with biomass pyrolysis is central to understanding product selectivity and aiding catalyst design produce more valuable products. However, even network of relatively simple [Formula: see text]-D-glucose remains unresolved due its significant complexity in terms depth number major Here, a transition-state-guided exploration has been performed that provides complete pathways most experimental products text]-D-glucose. The resulting involves over 31,000 reactions transition states computed at semiempirical quantum chemistry level approximately 7,000 kinetically relevant characterized density function theory, comprising largest reported for pyrolysis. was conducted using graph-based rules explore reactivities intermediates an adaption Dijkstra algorithm identify intermediates. This policy surprisingly (re)identified products, many proposed by previous computational studies, also identified new low-barrier mechanisms resolve outstanding discrepancies between yields isotope labeling experiments. explanatory high yield hydroxymethylfurfural pathway contributes formation hydroxyacetaldehyde during glucose Due limited domain knowledge required generate this network, approach should be transferable other complex prediction problems

Language: Английский

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Uncertainty-Aware First-Principles Exploration of Chemical Reaction Networks

The Journal of Physical Chemistry A, Journal Year: 2024, Volume and Issue: 128(22), P. 4532 - 4547

Published: May 24, 2024

Exploring large chemical reaction networks with automated exploration approaches and accurate quantum methods can require prohibitively computational resources. Here, we present an approach that focuses on the kinetically relevant part of network by interweaving (i) large-scale reactions, (ii) identification parts through microkinetic modeling, (iii) quantification propagation uncertainties, (iv) refinement. Such uncertainty-aware a accuracy improvement has not been demonstrated before in fully mechanical approach. Uncertainties are identified local or global sensitivity analysis. The is refined rolling fashion during exploration. Moreover, uncertainties considered steering We demonstrate our for Eschenmoser–Claisen rearrangement reactions. analysis identifies only small number reactions compounds essential describing kinetics reliably, resulting efficient explorations without sacrificing requiring prior knowledge about chemistry unfolding.

Language: Английский

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Nanoscale chemical reaction exploration with a quantum magnifying glass

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: June 22, 2024

Abstract Nanoscopic systems exhibit diverse molecular substructures by which they facilitate specific functions. Theoretical models of them, aim at describing, understanding, and predicting these capabilities, are difficult to build. Viable quantum-classical hybrid come with challenges regarding atomistic structure construction quantum region selection. Moreover, if their dynamics mapped onto a state-to-state mechanism such as chemical reaction network, its exhaustive exploration will be impossible due the combinatorial explosion space. Here, we introduce “quantum magnifying glass” that allows one interactively manipulate nanoscale structures level. The glass seamlessly combines autonomous model parametrization, ultra-fast mechanical calculations, automated exploration. It represents an approach investigate complex sequences in physically consistent manner unprecedented effortlessness real time. We demonstrate features for reactions bio-macromolecules metal-organic frameworks, highlight general applicability.

Language: Английский

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Identify structures underlying out-of-equilibrium reaction networks with random graph analysis

Chemical Science, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

Network measures have proven very successful in identifying structural patterns complex systems (e.g., a living cell, neural network, the Internet). How such can be applied to understand rational and experimental design of chemical reaction networks (CRNs) is unknown. Here, we develop procedure model CRNs as mathematical graph on which network random analysis applied. We used an enzymatic CRN (for mass-action was previously developed) show that provides insights into its structure properties. Temporal analyses, particular, revealed when feedback interactions emerge indicating comprise various reactions are being added removed over time. envision procedure, including temporal method, could broadly chemistry characterize properties many other CRNs, promising data-driven future molecular ever greater complexity.

Language: Английский

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AUTOGRAPH: Chemical Reaction Networks in 3D

Journal of Chemical Information and Modeling, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 15, 2025

Understanding and analyzing large-scale reaction networks is a fundamental challenge due to their complexity size, often beyond human comprehension. In this paper, we introduce AUTOGRAPH, the first web-based tool designed for interactive three-dimensional (3D) visualization construction of networks. AUTOGRAPH emphasizes ease use, allowing users intuitively build, modify, explore individual in real time. The platform supports wide range formats, including CHEMKIN, ensuring compatibility seamless integration with existing data. Key features include advanced 3D techniques combined fast force-directed algorithm, shortest-path searching, filtering, facilitating in-depth exploration By providing detailed visualizations, our enhances users' ability comprehend, analyze, present complex networks, making it valuable resource researchers dealing intricate chemical systems.

Language: Английский

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Ten Problems in Polymer Reactivity Prediction

Macromolecules, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 17, 2025

Language: Английский

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