Theoretical study on the adsorption of CO2 molecules on the rutile TiO2(110)
The adsorption of CO2 molecules on the rutile TiO2(110)with oxygen vacancy were studied by the PBE functional and the plane wave ultra-soft pseudopotential.The adsorption energy,the density of state,the Mulliken charge distribution and the charge density difference of four adsorption models were ana-lyzed.The theoretical results show that the adsorption energy of CO2 molecule perpendicular to the surface is the largest,the adsorption energy of CO2 molecule tilted to the surface is slightly less than that of vertical ad-sorption,and the adsorption energy of CO2 molecule parallel to the surface is small.It is indicated that the sta-bility of vertical adsorption is the best.When the C atom in CO2 molecule is adsorbed to the surface,there is no obvious electron cloud overlap between the C atom and the surface Ti atom.However,when the O atom in CO2 molecule is absorbed to the surface,there is an obvious electron cloud overlap between the O atom and the surface Ti atom,which indicates that the Ti5c atom on the surface is inclined to bind with the O atom in CO2 molecule.In the four adsorption models,C2p or O2p electrons of CO2 contribute the peak of density of state near the Fermi level,and the vertical adsorption shows the most significant peak,which further confirms that vertical adsorption is the most stable.This work provides some reliable theoretical results for CO2 adsorption and capture on the rutile TiO2.
rutile TiO2CO2 surface adsorptiondensity functional theorydensity of statescharge density difference
NETL
NSTL
万方数据
