Abstract
Synthesis gas (CO+H2) conversion to CH4 and CH3OH over a MoP catalyst has been examined using density functional theory and a Mo6P3 cluster model of the MoP surface. A model of synthesis gas conversion was developed by calculating adsorption energies of all possible arrangements of stable surface intermediates on Mo6P3. For CH4 formation, the potential energy surface (PES) followed the route (Had addition at each step is assumed but not shown) COadCHOadCH2OadCH2OHadCH2.ad+H2OadCH3.ad+H2OadCH4+H2O and CH3OH followed COadCHOadCH2OadCH2OHadCH3OHad. The activation energy for the formation of CH3OH from hydroxymethyl (100.9kcal/mol) is higher than for the formation of methylene and water (40.3kcal/mol), suggesting that CH4 rather than CH3OH will be produced from synthesis gas over MoP catalysts.