Premium
First‐principle calculations on CO oxidation catalyzed by a gold nanoparticle
Author(s) -
Chen HsinTsung,
Chang JeeGong,
Ju ShinPon,
Chen HuiLung
Publication year - 2009
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.21314
Subject(s) - catalysis , exothermic reaction , chemistry , nanoparticle , density functional theory , activation energy , reaction mechanism , atom (system on chip) , transition state , activation barrier , redox , molecule , photochemistry , computational chemistry , nanotechnology , inorganic chemistry , materials science , organic chemistry , computer science , embedded system
Abstract We have elucidated the mechanism of CO oxidation catalyzed by gold nanoparticles through first‐principle density‐functional theory (DFT) calculations. Calculations on selected model show that the low‐coordinated Au atoms of the Au 29 nanoparticle carry slightly negative charges, which enhance the O 2 binding energy compared with the corresponding bulk surfaces. Two reaction pathways of the CO oxidation were considered: the Eley–Rideal (ER) and Langmuir–Hinshelwood (LH). The overall LH reaction O 2(ads) + CO (gas) → O 2(ads) + CO (ads) → OOCO (ads) → O (ads) + CO 2(gas) is calculated to be exothermic by 3.72 eV; the potential energies of the two transition states ( TS LH1 and TS LH2 ) are smaller than the reactants, indicating that no net activation energy is required for this process. The CO oxidation via ER reaction Au 29 + O 2(gas) + CO (gas) → Au 29 –O 2(ads) + CO (gas) → Au 29 –CO 3(ads) → Au 29 –O (ads) + CO 2(gas) requires an overall activation barrier of 0.19 eV, and the formation of Au 29 –CO 3(ads) intermediate possesses high exothermicity of 4.33 eV, indicating that this process may compete with the LH mechanism. Thereafter, a second CO molecule can react with the remaining O atom via the ER mechanism with a very small barrier (0.03 eV). Our calculations suggest that the CO oxidation catalyzed by the Au 29 nanoparticle is likely to occur at or even below room temperature. To gain insights into high‐catalytic activity of the gold nanoparticles, the interaction nature between adsorbate and substrate is also analyzed by the detailed electronic analysis. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010