Methane is an extremely stable molecule, a major component of natural gas, and also one the most potent greenhouse gases contributing to global warming. Consequently, capture activation methane challenging intensively studied topic. A research goal find systems that can activate methane, even at low temperatures. Here, combining ultrahigh vacuum catalytic experiments, X-ray photoemission spectra, accurate density functional theory (DFT) based calculations, we show small Ni clusters dispersed...

The molecular mechanism of CO2 hydrogenation on a Ni(111) surface has been thoroughly investigated by means periodic density functional theory calculations, including dispersion interactions, along with accurate kinetic Monte Carlo simulations, lateral interactions between the adsorbates. present reaction model involves 25 different species and total 86 elementary processes, adsorptions, desorptions, chemical steps, diffusions. network accounts for three mechanisms reverse water-gas shift...

Kolbe electrolysis has been proposed as an efficient electro-oxidation process to synthesize (un)symmetrical dimers from biomass-based carboxylic acids, but its mechanism remains controversial. In this work, we develop a microkinetic model based on density functional theory study the reaction of acetic acid (CH3COOH) both pristine and partially oxidized Pt anodes. We show that shift in rate-determining step oxygen evolution (OER) Pt(111)@α-PtO2 surface OH∗ formation H2O adsorption gives rise...

Transition metal carbides (TMCs) constitute excellent alternatives to traditional oxide-based supports for small particles, leading strong metal–support interactions, which drastically modify the catalytic properties of supported atoms. Moreover, they possess extremely high melting points and good resistance carbon deposition sulfur poisoning, activities some TMCs per se have been shown be similar those Pt-group metals a considerable number reactions. Therefore, use as can give rise...

Transition Metal Carbides (TMCs) are proposed as viable replacements for scarce and expensive late Metals (TMs) heterogeneous catalysis involving hydrogenation reactions or steps.

The deposition of small transition metal (TM) clusters on carbides (TMC) gives rise to bifunctional catalysts with multiple active sites. This family single-cluster (SCCs) offers exciting opportunities for enabling a wider range chemical reactions owing their strong metal–support interactions, which drastically modify the catalytic properties supported atoms. In this work, we use first-principles Kinetic Monte Carlo (KMC) simulations investigate conversion CO2 and CH4 Pt/HfC, was identified...

The interaction between metal particles and the support in heterogeneous catalysis has been subject of a large number studies. While strong metal–support interactions can lead to deleterious catalyst deactivation underlying mechanism is well understood, other cases effect may beneficially enhance catalytic activity and/or selectivity with no clear picture chemistry involved. Strong make Au nanoparticles dispersed on MoC highly active for low-temperature water-gas shift reaction (WGSR). Here,...

Abstract In the present article, we survey two common approaches widely used to study kinetics of heterogeneous catalytic reactions. These are kinetic Monte Carlo simulations and microkinetic modeling. We discuss typical assumptions, advantages, drawbacks, differences these methodologies. also illustrate some wrong concepts inaccurate procedures too often in this kind studies. Thus, several issues as for instance minimum energy diagrams, diffusion processes, lateral interactions, or accuracy...

Several materials composed of metal nanoclusters supported on transition carbides (TMCs) are studied via density functional theory, in view the promising catalytic properties demonstrated experimentally for selected TMC–metal combinations.

Predictive-quality computational modeling of heterogeneously catalyzed reactions has emerged as an important tool for the analysis and assessment activity trends. In contrast, more subtle selectivities selectivity trends still pose a significant challenge to prevalent microkinetic approaches that typically employ mean-field approximation (MFA). Here, we focus on CO hydrogenation Rh catalysts with possible products methane, acetaldehyde, ethanol, water. This reaction already been subjected...

The temporal evolution at the catalyst surface is a result of an intricate interplay between all involved microscopic events such as adsorption, desorption, diffusion, and bond breaking/formation steps, interaction with surrounding environment. By properly including these effects, kinetic Monte Carlo (kMC) simulations can accurately describe complexity real catalysts, unravel dominant reaction mechanisms provide fundamental understanding towards rational design novel catalysts. In this work,...

Two-dimensional porous MXenes with the formula M₂C (M = Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W) are proposed as very promising sorbent materials for carbon dioxide (CO₂) separation from methane (CH₄) in critical step of biogas upgrading.

Metal-water interfaces are central to understanding aqueous-phase heterogeneous catalytic processes. However, the explicit modeling of interface is still challenging as it necessitates extensive sampling interfaces' degrees freedom. Herein, we use ab initio molecular dynamics (AIMD) simulations study adsorption furfural, a platform biomass chemical on several catalytically relevant metal-water (Pt, Rh, Pd, Cu, and Au) at low coverages. We find that furfural destabilized all compared...

The search for cheap and active materials the capture activation of CO2 has led to many efforts aimed at developing new catalysts. In this context, earth-abundant transition metal carbides (TMCs) have emerged as promising candidates, garnering increased attention in recent decades due their exceptional refractory properties resistance sintering, coking, sulfur poisoning. work, we assess use Group 5 TMCs (VC, NbC, TaC) potential carbon sequestration/utilization technologies by combining...

The molecular mechanisms of the water gas shift reaction on Cu(321) have been chosen to investigate effect dispersion terms description energy profile and rates. present study based periodic DFT calculations shows that including does not change qualitative picture overall reaction, maintaining rate determining step predominant route. However, is different for adsorbates - reactants, intermediates or products with a clear net no compensation errors. Thus, in OH + → H2O O process effects imply...

Molybdenum carbide breaks methane by going nano.

Small Ni particles supported on TiC(001) were shown to display a very high activity for the catalytic hydrogenation of CO2 but underlying chemistry is, large extent, unknown. Here, by means periodic density functional theory (DFT) calculations with BEEF–vdW functional, we explore adsorption and subsequent dissociation H2 several Nin clusters (n = 4, 9, 13, 16) compare results those obtained bare Ni(111) surfaces using exactly same computational approach. The reveal that Nin/TiC system...