Theoretical study of the water effect on CO adsorbed over Au/SAPO-11 catalysts

In this study, we carried out two-layer ONIOM calculations to determine the energy changes for the gold-exchanged silicoaluminophospate (Au/SAPO-11) catalysts interaction with CO, H₂, and H₂O molecules, and the formation of possible intermediate species, such as HO = C = OH. The results reveal that the [CO(OH)Au(H)]⁺ and [H⁺OHAu]⁺ species formation as well as HCOOH and the HO=C=OH intermediate formation are energetically favorable processes. This work shows for the first time the potential ability of the Au/SAPO-11 catalyst to perform water gas shift reaction (WGS).