We present a combined density functional theory (DFT) and Kinetic Monte Carlo (KMC) study of the water gas shift (WGS) reaction on the Pd(100) surface. We propose a mechanism comprising both the redox and the associative pathways for the WGS within a single framework, which consists of seven core elementary steps, which in turn involve splitting of a water molecule followed by the production of an H-atom and an OH-species on the Pd(100) surface. In the following steps, these intermediates then recombine with each other and with CO leading to the evolution of CO, and H. Seven other elementary steps, involving the diffusion and adsorption of the surface intermediate species are also considered for a complete description of the mechanism. The geometrical and electronic properties of each of the reactants, products, and the transition states of the core elementary steps are presented. We also discuss the analysis of Bader charges and spin densities for the reactants, transition states and the products of these elementary steps. Our study indicates that the WGS reaction progresses simultaneously via the direct oxidation and the carboxyl paths on the Pd(100) surface.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1039/c9cp05476f | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Hydride-Induced Reconstruction of Pd Electrode Surfaces: A Combined Computational and Experimental Study.
Adv Mater
December 2024
Physics of Energy Conversion and Storage, Department of Physics, Technical University of Munich, James-Franck-Straße 1, 85748, Garching, Germany.
Designing electrocatalysts with optimal activity and selectivity relies on a thorough understanding of the surface structure under reaction conditions. In this study, experimental and computational approaches are combined to elucidate reconstruction processes on low-index Pd surfaces during H-insertion following proton electroreduction. While electrochemical scanning tunneling microscopy clearly reveals pronounced surface roughening and morphological changes on Pd(111), Pd(110), and Pd(100) surfaces during cyclic voltammetry, a complementary analysis using inductively coupled plasma mass spectrometry excludes Pd dissolution as the primary cause of the observed restructuring.
View Article and Find Full Text PDFAcetylene Semihydrogenation over Pd-Bi Intermetallic Compounds: A DFT Combined with Microkinetic Modeling Study.
Langmuir
September 2024
Frontiers Science Center for New Organic Matter, Tianjin Key Lab and Molecule-Based Material Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China.
Acetylene semihydrogenation is an important process both theoretically and experimentally. Pure Pd catalysts usually suffer from limited selectivity for ethylene products and poor stability. Pd-Bi bimetallic compounds are synthesized and show not only excellent catalytic performance but also remarkable long-term stability.
View Article and Find Full Text PDFInfluence of Pd-Layer Thickness on Bonding Reliability of Pd-Coated Cu Wire.
Micromachines (Basel)
July 2024
School of Mechanical and Power Engineering, Henan Polytechnic University, Jiaozuo 454000, China.
In this paper, three Pd-coated Cu (PCC) wires with different Pd-layer thicknesses were used to make bonding samples, and the influence of Pd-layer thickness on the reliability of bonded points before and after a high-temperature storage test was studied. The results show that smaller bonding pressure and ultrasonic power lead to insufficient plastic deformation of the ball-bonded point, which also leads to small contact area with the pad and low bonding strength. Excessive bonding pressure and ultrasonic power will lead to 'scratch' on the surface of the pad and large-scale Ag spatter.
View Article and Find Full Text PDFSelective Cleavage of α-Olefins to Produce Acetylene and Hydrogen.
J Am Chem Soc
May 2024
BNLMS, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Article Synopsis
- Acetylene production from mixed α-olefins offers an eco-friendly method for selectively breaking carbon-carbon (C-C) bonds using Pd(100) surfaces.
- The process involves the thermal cleavage of α-olefins, leading to the formation of acetylene and hydrogen, with high selectivity due to the unique 4-fold hollow sites on the Pd surface.
- A critical challenge is that acetylene tends to remain on the surface; however, using surface alloying with gold (Au) successfully helps release acetylene as a gas, presenting a cost-effective way to produce acetylene and hydrogen.
The surface chemistry of norbornadiene and norbornene on Pd(111) and Pd(100): a comparative DFT study.
J Mol Model
October 2023
MIREA - Russian Technological University, Lomonosov Institute of Fine Chemical Technologies, 86 Vernadsky Avenue, 119571, Moscow, Russian Federation.
Context: The interaction of norbornadiene (NBD) and norbornene (NBE) with the palladium (111) and (100) surfaces have been investigated using density functional theory (DFT). Five configurations of adsorbed NBD may be formed on Pd(111): endo-tetra-σ, endo-di-σ,π, endo-di-π, exo-di-σ, and exo-π. The NBE molecule adsorbed on Pd(111) may exist in 4 configurations: endo-di-σ, endo-π, exo-di-σ, and exo-π.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!