Chemisorption

About: Chemisorption is a research topic. Over the lifetime, 16298 publications have been published within this topic receiving 554989 citations.

Evaluation of corrosion inhibition performance of phosphorus polymer for carbon steel in [1 M] HCl: Computational studies (DFT, MC and MD simulations)

Abstract: Pentaglycidyl ether pentabisphenol A of phosphorus (PGEPBAP) phosphorus polymer was investigated as corrosion inhibition for carbon steel in aggressive solution using potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), weight loss (WL), scanning electron microscope (SEM), density functional theory (DFT), electrostatic potential (ESP), radial distribution function (RDF), molecular dynamics (MD) and Monte Carlo (MC) simulations. The higher inhibition efficiencies for PDP, EIS and WL studies at 10−3 M concentration of PGEPBA phosphorus polymer are 94.18 %, 91.79 % and 91.3 %, respectively. ΔEcorr (23.7 mV) value of PGEPBAP phosphorus polymer is lower than 85 mV has been assigned to mixed type inhibitor. PGEPBAP formed protective film on carbon steel surface by adsorption according to Langmuir adsorption isotherm. SEM morphology suggested that PGEPBAP could effectively block acid attack by chemisorption on metal surface. To evaluate the polymer inhibitor and potential mechanism were especially realized DFT, ESP, RDF, MD and MC simulations.

The bare and acetylene chemisorbed si(001) surface, and the mechanism of acetylene chemisorption

Abstract: Both cluster and extended slab models for the bare Si(OO1) surface and for acetylene chemisorbed on that surface were studied by various theoretical methods. Our calculations point to a buckled Si-Si dimer on the bare reconstructed surface. Acetylene adsorbs onto the dimer to form a four-member disilacyclobutene ring without breaking the Si-Si bond. Upon acetylene chemisorption, the buckled dimers become symmetric. The surface reaction is orbital symmetry-forbidden. A likely pathway for the cycloaddition, via a n-complex precursor and a biradical intermediate, is suggested. Introduction Silicon is at the heart of our information age. The most common form of this element has the beautiful bulk structure of diamond (1, a conventional unit cell), in which every Si atom is covalently bonded to four Si’s. Both the bulk material and silicon surfaces are of technological importance. If a silicon crystal is cut, one of the simplest surfaces one gets, and one very well studied, is Si(OO1). The unreconstructed surface would expose a two-dimensional square lattice (2; a conventional unit cell is outlined), with each surface

A density functional theory study of hydroxyl and the intermediate in the water formation reaction on Pt

Abstract: Density functional theory has been used to study the adsorption of hydroxyl at low and high coverages and also to investigate the nature of the intermediate in the H2O formation reaction on Pt(111). At low coverages [1/9 of a monolayer (ML) to 1/3 ML] OH binds preferentially at bridge and top sites with a chemisorption energy of ∼2.25 eV. At high coverages (1/2 ML to 1 ML) H bonding between adjacent hydroxyls causes: (i) an enhancement in OH chemisorption energy by about 15%; (ii) a strong preference for OH adsorption at top sites; and (iii) the formation of OH networks. The activation energy for the diffusion of isolated OH groups along close packed rows of Pt atoms is 0.1 eV. This low barrier coupled with H bonding between neighboring OH groups indicates that hydroxyls are susceptible to island formation at low coverages. Pure OH as well as coadsorbed OH and H can be ruled out as the observed low temperature intermediate in the water formation reaction. Instead we suggest that the intermediate consists ...