Development of a thiophene derivative modified LDH coating for Mg alloy corrosion protection.

A new thiophene derivative corrosion inhibitor (CI) was developed to functionalize the layered double hydroxide (LDH) primer on Mg alloy to enhance corrosion protection. Compared with bare LDH coating, the composite coatings consisting of a MgAl-LDH primer and an outer CI layer showed highly compact surface structures without large pores and gaps, thereby indicating the enhanced capability to resist the penetration of corrosive species. Electrochemical tests revealed that the MgAl-LDH film modified with the newly synthesized CI exhibited higher charge transfer resistance and lower corrosion current density than films modified with commercial CIs. The highest enhancement in corrosion resistance was linked to the film's ability to repair physical damage by forming precipitates through chemical complexation and adsorption of the CIs. These findings open up new opportunities for the design and synthesis of a thiophene-contained inhibitor to modify LDH films and to obtain a composite coating with superior corrosion protection

Design of Single Atom Catalysts

Over the past decade, computational modeling based on density functional theory (DFT) calculations provides a deep insight into the catalytic mechanism of single-atom catalysts (SACs) and paves way for high-throughput screening of promising SACs. This review summarizes computational methods for the analysis of the electronic structures and catalytic performance of SACs, as well as introduces the utilization of descriptors for the computational design of SACs. We expect that future advances in computational methods will surely help to identify highly effective SACs for a wide variety of reactions

The structure, energetics and thermal evolution of SiGe nanotubes

The structure, energetics and thermal behavior of all the SiGe nanotubes in armchair and zigzag structures (n = 4-10) and two atomic arrangement types are investigated using the ab initio method and classical molecular dynamics simulations. Gearlike and puckering configurations of SiGe nanotubes are obtained. The simulation results indicate that large-diameter nanotubes are more stable than small-diameter ones. Moreover, the type1 (alternating atom arrangement type) zigzag nanotubes are always more energetically favorable than the type2 (layered atom arrangement type) zigzag nanotubes. During the melting process, the melting-like structural transformations from the initial nanotube to the compact nanowire take place first, and then the compact nanowires are changed into agglomerate structures at higher temperature. It is also found that the melting-like temperatures of Ge-substituted silicon nanotubes decrease with increase of the Ge concentration. © 2009 IOP Publishing Ltd.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Influence of the environment on equilibrium properties of Au-Pd clusters

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Theoretical study of the structures of MgO(1 0 0)-supported Au clusters

A theoretical method, which combines the first-principle calculations and a canonical Monte Carlo (CMC) simulation, was used to study the structures of Au clusters with sizes of 25-54 atoms supported on the MgO(1 0 0) surface. Based on a potential energy surface (PES) fitted to the first-principle calculations, an effective approach was derived to model the Au-MgO(1 0 0) interaction. The second moment approximation to the tight-binding potential (TB-SMA) was used to model the Au-Au interactions in the CMC simulation. It is found that the Au clusters with sizes of 25-54 atoms supported on the MgO(1 0 0) surface possess an ordered layered fcc epitaxial structure. © 2009 Elsevier B.V. All rights reserved.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Ni (111)-supported graphene as a potential catalyst for high-efficient CO oxidation

The investigations of hybrid graphene layers on metal surfaces have attracted widespread attention from both experimental and theoretical scientists, but the catalytic properties of well-known Ni (111)-supported graphene are still unclear. In this work, an unreported C2O2-Langmuir-Hinshelwood (C2O2-LH) mechanism is proposed for CO oxidation (COox) on the Ni (111) supported-graphene surface by density functional theory (DFF) calculations. Our results show that two CO molecules can chemisorb on the Ni (111)-supported graphene merging into the chemisorbed ethylene dione complex (C2O2). Then, the coadsorption of C2O2 and O-2 molecules can form the C2O2 annulus on the Ni (111)-supported graphene. Finally, the C2O2 annulus produces two CO2 molecules through the formation of a ring-like intermediate product (R-L Inter). Specially, we find that this new C2O2-LH mechanism with the co-adsorption of C2O2 and O-2 molecules as the first step achieves much lower energy barrier compared with the prevailing belief of the Eley-Rideal (ER) mechanism with the O-2 activation as the first step. These results suggest that the Ni (111)-supported graphene could be a potential and high-efficient catalyst for COox, which also open fundamental insights into the new reaction mechanism for COox on nanocatalysts. (C) 2017 Elsevier Ltd. All rights reserved.</p