Atomistic investigation on the kinetics behavior of vapour adsorption and cluster evolutions using statistical rate theory approach

The kinetics behavior of vapor adsorption on solid surface in an isobaric-isothermal system are investigated by means of molecular dynamics simulations combined with theoretical studies through statistical rate theory approach....

On the influence of water on urea condensation reactions: a theoretical study

The influence of water molecules on the kinetics of urea condensation reactions was studied with high-level quantum chemical methods and statistical rate theory. The study focuses on the production of biuret, triuret, and cyanuric acid from urea because of their relevance as unwanted byproducts in the urea-based selective catalytic reduction (urea-SCR) exhaust after treatment of Diesel engines. In order to characterize the potential energy surfaces and molecular reaction pathways, calculations with explicitly-correlated coupled-cluster methods were performed. It turned out that the reactions proceed via pre-reactive complexes and the inclusion of one or two water molecules into the condensation mechanisms leads to a decrease of the energy barriers. This effect is particularly pronounced in the production of biuret. Due to the pre-reactive equilibria, the rates of the overall reactions can increase or decrease by incorporating water into the mechanism, depending on the temperature and water concentration. Under the conditions of urea-SCR, the studied reactions are too slow to contribute to the observed byproduct formation.

Binary Adsorption of Two Textile Dyes onto Diatomite: Kinetic and Isotherm Study

Nowadays, many studies focus only on the removal of dyes from water in single solution. In real applications the colored effluents contain more than one component to eliminate. In this study, the adsorption of two textile dyes – Red Bemacid-ETL (RB-ETL) and Bezaktiv Turquoise Blue-VG (BTB-VG) – was investigated in a binary mixture. The derivative spectrophotometry was used to determine the specific wavelength for each dye. The effect of pH, contact time and initial dye concentrations was considered. The results show that diatomite has a good potential to eliminate both of dyes simultaneously. The competitive statistical rate theory model fits the adsorption kinetic data of the binary system well. The adsorption isotherm data for both dyes is well described by multicomponent Langmuir isotherm model. A high competition effect was observed, but BTB-VG dye was more selectively adsorbed by heat treated diatomite than RB-ETL dye.

A Trajectory-Based Method to Explore Reaction Mechanisms

The tsscds method, recently developed in our group, discovers chemical reaction mechanisms with minimal human intervention. It employs accelerated molecular dynamics, spectral graph theory, statistical rate theory and stochastic simulations to uncover chemical reaction paths and to solve the kinetics at the experimental conditions. In the present review, its application to solve mechanistic/kinetics problems in different research areas will be presented. Examples will be given of reactions involved in photodissociation dynamics, mass spectrometry, combustion chemistry and organometallic catalysis. Some planned improvements will also be described.

A Trajectory-Based Method to Explore Reaction Mechanisms

The tsscds method, recently developed in our group, discovers chemical reaction mechanisms with minimal human intervention. It employs accelerated molecular dynamics, spectral graph theory, statistical rate theory and stochastic simulations to uncover chemical reaction paths and to solve the kinetics at the experimental conditions. In the present review, its application to solve mechanistic/kinetics problems in different research areas will be presented. Examples will be given of reactions involved in photodissociation dynamics, mass spectrometry, combustion chemistry and organometallic catalysis. Some planned improvements will also be described.

A Trajectory-Based Method to Explore Reaction Mechanisms

The method tsscds, recently developed in our group, discovers chemical reaction mechanisms with minimal human intervention. It employs accelerated molecular dynamics, spectral graph theory, statistical rate theory and stochastic simulations to uncover chemical reaction paths and to solve the kinetics at the experimental conditions. In the present review, its application to solve mechanistic/kinetics problems in different research areas will be presented. Examples will be given of reactions involved in photodissociation dynamics, mass spectrometry, combustion chemistry and organometallic catalysis. Some planned improvements will also be described. The source code can be downloaded from: http://forge.cesga.es/wiki/g/tsscds/HomePage

A Trajectory-Based Method to Explore Reactions Mechanisms

The method tsscds, recently developed in our group, discovers chemical reaction mechanisms with minimal human intervention. It employs accelerated molecular dynamics, spectral graph theory, statistical rate theory and stochastic simulations to uncover chemical reaction paths and to solve the kinetics at the experimental conditions. In the present review, its application to solve mechanistic/kinetics problems in different research areas will be presented. Examples will be given of reactions involved in photodissociation dynamics, mass spectrometry, combustion chemistry and organometallic catalysis. The source code can be downloaded from: http://forge.cesga.es/wiki/g/tsscds/HomePage