skip to main content

SciTech ConnectSciTech Connect

Title: Monte Carlo simulations of surface reactions: NO reduction by CO or H{sub 2}

The development of surface science has given an opportunity to investigate the process of heterogeneous catalysis at a molecular level. In this way there has been a great progress in understanding the mechanism in NO decomposition. Modeling has been an very important tool in this goal. In this work we analyze the reactions NO+H{sub 2} and NO+CO. The extremely narrow production peak of N{sub 2} and CO{sub 2} which occurs in the reaction of NO+CO on Pt(100), a phenomenon known as “surface explosion,” is studied using a dynamic Monte Carlo method on a square lattice at low pressure under isothermal conditions. The catalytic reduction of nitric oxide by hydrogen over a Pt surface is also studied by using a dynamic Monte Carlo. Using a Langmuir-Hinshelwod mechanism of reaction, a simplified model with only four adsorbed species (NO, H, O, and N) is constructed. The effect on NO dissociation rate, the limiting step in the whole reaction, is inhibited by coadsorbed NO and H{sub 2} molecules, and is enhanced both by the presence of empty sites and adsorbed N atoms as nearest-neighbors. In these simulations experimental parameters values are included, such as: adsorption, desorption and diffusion of the reactants. The phenomenonmore » is studied changing the temperature in the range of 300–550 K. The modeling reproduces well observed TPD and TPR experimental results and allows a visualization of the spatial development of the surface explosion.« less
Authors:
;  [1] ;  [2]
  1. Departamento de Física y Química Teórica, Facultad de Química, Universidad Nacional Autónoma de México, Circuito Escolar s/n, Ciudad Universitaria, 04510 México Distrito Federal (Mexico)
  2. Departamento de Ciencias Naturales, Universidad Autónoma Metropolitana-Cuajimalpa, Av. Vasco de Quiroga 4871, Col. Santa Fe Cuajimalpa, 05348 México Distrito Federal (Mexico)
Publication Date:
OSTI Identifier:
22264072
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1579; Journal Issue: 1; Conference: 5. Leopoldo Garcia-Colin Mexican meeting on mathematical and experimental physics, Mexico City (Mexico), 9-13 Sep 2013; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ADSORPTION; CARBON MONOXIDE; COMPUTERIZED SIMULATION; DECOMPOSITION; DESORPTION; HYDROGEN; MONTE CARLO METHOD; NITRIC OXIDE; TETRAGONAL LATTICES