Cluster modeling and coordination structures of Cu+ ions in Al-incorporated Cu-MEL catalysts - a density functional theory study

A density-functional-based cluster modeling was implemented on the Al-incorporated Cu-MEL zeolite catalyst (Cu-ZSM-11) to probe the electronic, energetic and structural features of the active sites of the catalyst at the B3LYP/6-311+G* and M06/Def2-TZVP levels. The HOMO-LUMO energy gap fell into the range of 3.31-5.15 eV at TD-BH&HLYP/6-311+G* with the lowest magnitude for the I-Cu and M1-Cu clusters. Population-averaged values for the exchange enthalpy and binding energy were also calculated, being approximately 125 and 171 kcal/mol, respectively.