Pyridine adsorption and reaction on Mo(110) and C/N-Mo(110): experiment and modeling

被引:10
作者
Abdallah, WA [1 ]
Nelson, AE [1 ]
Gray, MR [1 ]
机构
[1] Univ Alberta, Dept Chem & Mat Engn, Edmonton, AB T6G 2G6, Canada
基金
加拿大自然科学与工程研究理事会;
关键词
molybdenum; thermal desorption; density functional calculations; chemisorption;
D O I
10.1016/j.susc.2004.07.037
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The adsorption of pyridine (C5H5N) on clean and carbon/nitrogen-modified Mo(110) surfaces has been investigated using temperature-programmed desorption (TPD) and density-functional theory (DFT) calculations. Pyridine adsorbs and decomposes on Mo(110) and C/N-Mo(110) at temperatures less than 530 K. Molecular pyridine desorption on clean Mo(110) occurs at temperatures of 375 5 K (E-ads = 23.5 +/- 0.3 kcal mol(-1)) and 530 5 K (E-ads = 33.6 +/- 0.3 kcal mol(-1)). At higher exposures, a multilayer physisorption peak was also observed at 260 K (E-ads = 10.4 +/- 0.3 kcal mol(-1)). Pyridine decomposition on Mo(110) results in surface carbon and nitrogen accumulation, and gaseous dihydrogen. The energetics of various pyridine adsorption modes were calculated with DFT in order to identify the bonding modes resulting in molecular desorption and surface decomposition. The DFT calculations suggest that pyridine initially adsorbs as eta(6)-Py-0degrees coordination followed by eta(1)(N)-Py-90degrees adsorption on clean Mo(110), and surface heating is suggested to result in the transformation of a portion of eta(6)-py-0degrees pyridine to surface alpha-pyridyl species (mu(2),eta(2)(N,C2)-Pyridyl, eta(2)(N,C2)-Pyridyl) that further decompose to surface carbon and nitrogen and desorbing dihydrogen on clean Mo(110). (C) 2004 Elsevier B.V. All rights reserved.
引用
收藏
页码:193 / 206
页数:14
相关论文
共 55 条
[1]   Transformation of pyridine to α-pyridyl on W(110) as probed by vibrational spectroscopy:: Experiments and calculations [J].
Andersson, MP ;
Uvdal, P .
JOURNAL OF PHYSICAL CHEMISTRY B, 2001, 105 (39) :9458-9462
[2]  
[Anonymous], 1994, UPGRADING PETROLEUM
[3]   ELECTRONIC EXCITATIONS OF BENZENE, PYRIDINE, AND PYRAZINE ADSORBED ON AG(111) [J].
AVOURIS, P ;
DEMUTH, JE .
JOURNAL OF CHEMICAL PHYSICS, 1981, 75 (10) :4783-4794
[4]   ELECTRONICALLY EXCITED-STATES OF CHEMISORBED MOLECULES [J].
AVOURIS, P ;
DINARDO, NJ ;
DEMUTH, JE .
JOURNAL OF CHEMICAL PHYSICS, 1984, 80 (01) :491-502
[5]   ORIENTATIONAL PHASE-TRANSITION IN THE SYSTEM PYRIDINE AG(111) - A NEAR-EDGE X-RAY-ABSORPTION FINE-STRUCTURE STUDY [J].
BADER, M ;
HAASE, J ;
FRANK, KH ;
PUSCHMANN, A ;
OTTO, A .
PHYSICAL REVIEW LETTERS, 1986, 56 (18) :1921-1924
[6]   SELECTION-RULES IN PHOTOEMISSION FROM ADSORBATES - PYRIDINE ADSORBED ON COPPER [J].
BANDY, BJ ;
LLOYD, DR ;
RICHARDSON, NV .
SURFACE SCIENCE, 1979, 89 (1-3) :344-353
[7]   A MULTICENTER NUMERICAL-INTEGRATION SCHEME FOR POLYATOMIC-MOLECULES [J].
BECKE, AD .
JOURNAL OF CHEMICAL PHYSICS, 1988, 88 (04) :2547-2553
[8]  
Boudart M., 1981, Journal de Chimie Physique et de Physico-Chimie Biologique, V78, P987
[9]  
CHAUDRET B, 1990, NEW J CHEM, V14, P331
[10]   FACILE PREPARATION OF PI-ARENE COMPLEXES OF RUTHENIUM [(ETA-5-C5ME5)RU(ARENE)]X INCLUDING A PI-PYRIDINE AND THE 1ST PI-FURAN DERIVATIVES [J].
CHAUDRET, B ;
JALON, FA .
JOURNAL OF THE CHEMICAL SOCIETY-CHEMICAL COMMUNICATIONS, 1988, (11) :711-713