A combined operando XAS/DRIFTS study to elucidate the influence of Bi on Pt/Al2O3 CO oxidation catalysts

The proposed combined operando X-ray Absorption Spectroscopy (XAS) & Infrared Spectroscopy (DRIFTS) experiments will focus on elucidating the influence of Bi as a promotor element on the structure and electronic properties of a Pt/Al2O3 Diesel Oxidation Catalyst for the CO oxidation reaction. It has been well established that Pt catalysts suffer from CO poisoning at low temperatures. Our previous results show that he addition of Bi prevents CO poisoning and lowers T50%, the temperature at which 50% of CO is converted to CO2. However, the way in which Bi promotes the catalysts is not yet well understood. The proposed operando XAS/DRIFTS characterization study will allow us to observe the evolution of the Pt active site with XAS, while simultaneously probing the electronic properties with CO as a molecular probe with DRIFTS, during CO oxidation reaction monitored by online MS. These transient data will shed light on the effect of Bi on the (electronic) structure of the Pt/Al2O3 catalyst.