Hydrogen generation by the reaction of H2O with Al2O3-based materials: a computational analysis

2015 ◽  
Vol 17 (10) ◽  
pp. 6834-6843 ◽  
Author(s):  
Yu-Huan Lu ◽  
Hsin-Tsung Chen
Keyword(s):  
First Principles ◽  
Reaction Mechanisms ◽  
Md Simulation ◽  
Computational Analysis ◽  
Hydrogen Generation

By combined DFT and first-principles MD simulation, we propose detailed reaction mechanisms for H2O splitting and hydrogen generation on Al2O3-based materials.

Computationally Augmented Retrosynthesis: Total Synthesis of Paspaline A and Emindole PB

2018 ◽  
Author(s):  
Timothy Newhouse ◽  
Daria E. Kim ◽  
Joshua E. Zweig
Keyword(s):  
Chemical Synthesis ◽  
Total Synthesis ◽  
Small Molecules ◽  
First Principles ◽  
Quantum Chemical ◽  
Computational Analysis ◽  
Empirical Evaluation ◽  
Synthetic Strategy ◽  
Catalyzed Reactions ◽  
Enzyme Catalyzed Reactions

The diverse molecular architectures of terpene natural products are assembled by exquisite enzyme-catalyzed reactions. Successful recapitulation of these transformations using chemical synthesis is hard to predict from first principles and therefore challenging to execute. A means of evaluating the feasibility of such chemical reactions would greatly enable the development of concise syntheses of complex small molecules. Herein, we report the computational analysis of the energetic favorability of a key bio-inspired transformation, which we use to inform our synthetic strategy. This approach was applied to synthesize two constituents of the historically challenging indole diterpenoid class, resulting in a concise route to (–)-paspaline A in 9 steps from commercially available materials and the first pathway to and structural confirmation of emindole PB in 13 steps. This work highlights how traditional retrosynthetic design can be augmented with quantum chemical calculations to reveal energetically feasible synthetic disconnections, minimizing time-consuming and expensive empirical evaluation.

scholarly journals Fabrication of Robust Hydrogen Evolution Reaction Electrocatalyst Using Ag2Se by Vacuum Evaporation

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1460
Author(s):  
Sajjad Hussain ◽  
Jinwoong Chae ◽  
Kamran Akbar ◽  
Dhanasekaran Vikraman ◽  
Linh Truong ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
First Principles ◽  
Hydrogen Adsorption ◽  
Hydrogen Generation ◽  
Low Cost ◽  
First Principles Calculations ◽  
Electrochemical Surface Area ◽  
Complex Catalyst ◽  
Catalyst Synthesis

Much research has been done on reliable and low-cost electrocatalysts for hydrogen generation by water splitting. In this study, we synthesized thin films of silver selenide (Ag2Se) using a simple thermal evaporation route and demonstrated their electrocatalytic hydrogen evolution reaction (HER) activity. The Ag2Se catalysts show improved electrochemical surface area and good HER electrocatalytic behavior (367 mV overpotential @ 10 mA·cm−2, exchange current density: ~1.02 × 10−3 mA·cm−2, and Tafel slope: 53 mV·dec−1) in an acidic medium). The reliability was checked in 0.5 M sulfuric acid over 20 h. Our first-principles calculations show the optimal energy of hydrogen adsorption, which is consistent with experimental results. The works could be further extended for finding a new catalyst by associating the selenide, sulfide or telluride-based materials without complex catalyst synthesis procedures.

First Principles Molecular Simulations of Soda-Lime-Silica Glass

2008 ◽  
Vol 39-40 ◽  
pp. 85-88 ◽  
Author(s):  
Jan Macháček ◽  
Soňa Charvátová ◽  
Ondrej Gedeon ◽  
Marek Liška
Keyword(s):  
First Principles ◽  
Md Simulation ◽  
Soda Lime ◽  
Md Simulations ◽  
Distribution Functions ◽  
Basis Set ◽  
Ab Initio Molecular Dynamics ◽  
Radial Distribution Functions ◽  
Coordination Numbers ◽  
Soda Lime Silica Glass

This work aims to explore possible applications of the ab initio molecular dynamics (MD) in modeling of the soda-lime-silica (NCS) glass and melt doped with admixtures. Preparation of the basic glass (15.8 wt.% Na2O, 10.5 wt.% CaO, and 73.7 wt.% SiO2) by the MD simulation from scratch is described. The structure analysis of the NCS glass is presented in the form of total and partial radial distribution functions (RDF), coordination numbers, and fractions of Qn units. The reasonable first neighbor distances were obtained, even if a rather small basis set of electronic wavefunctions and softer pseudopotentials for atomic core regions were applied. All major discrepancies in the first neighbor distances can be easily explained, and the results can be improved if needed. The Qn distribution shows higher disproportionation of Q3 than NMR and Raman experimental data, however, it is lower than previous classical MD simulations.

Discharge Reaction Mechanisms in Na/FeS2 Batteries: First-Principles Calculations

2015 ◽  
Vol 84 (12) ◽  
pp. 124709 ◽  
Author(s):  
Hiroyoshi Momida ◽  
Ayuko Kitajou ◽  
Shigeto Okada ◽  
Tomoki Yamashita ◽  
Tamio Oguchi
Keyword(s):  
First Principles ◽  
Reaction Mechanisms ◽  
First Principles Calculations ◽  
Discharge Reaction

What Occurs by Replacing Mn2+with Co2+in Human Arginase I: First-Principles Computational Analysis

2012 ◽  
Vol 52 (2) ◽  
pp. 655-659 ◽  
Author(s):  
Tiziana Marino ◽  
Nino Russo ◽  
Marirosa Toscano
Keyword(s):  
First Principles ◽  
Computational Analysis ◽  
Arginase I

Graphene sheet with periodic vacancy: A first principles study

2021 ◽  
Author(s):  
Deepti Maikhuri ◽  
Jaiparkash Jaiparkash ◽  
Haider Abbas
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Electronic Structure ◽  
Band Gap ◽  
Graphene Sheet ◽  
First Principles ◽  
Density Functional ◽  
Computational Analysis ◽  
Functional Theory ◽  
First Principles Study

Abstract We present a comprehensive first-principles study of the electronic structure of graphene sheet with periodic vacancy. We report the structural, electronic, and magnetic properties of the graphene sheet with periodic vacancy that possess 48 C & 28 H atoms. Computational analysis based on density functional theory predicts that the periodic vacancy can modulate the properties of graphene sheet. Results show that periodic vacancies lead to the manipulation of band gap & could be utilized to tailor the electronic properties of the sheet. Also, it is found that, the graphene sheet with periodic vacancy is non-magnetic in nature.

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