Highly active and water-resistant Lanthanum-doped platinum-cobalt oxide catalysts for CO oxidation

The presence of interfacial sites between Pt-group metals and transition metal oxides can effectively improve the catalytic activity of Pt-group catalysts, but under moisture-rich conditions they suffer from severe deactivation due to water poisoning of the active sites. Here, we propose for the first time a Lanthanum (La)-doping strategy to improve the water-resistance of the Pt-based catalysts. We synthesized a Pt-CoO/Al 2 O 3 catalyst that is active for CO oxidation under dry conditions but deactivates rapidly under moisture. This rapid deactivation is overcome by La-doping, which delivers boosted activity (100 % CO conversion at  15 °C) and long-term on-stream stability. In situ X-ray absorption fine-structure and in situ diffuse reflectance infrared Fourier transform spectra revealed that the doped La, in the form of La 2 O 3 , plays dual roles of suppressing the carbonate formation on the active sites and modifying the electronic structure of Pt. The synergetic effects between La 2 O 3 and the active Pt−O−Co interfacial sites in La-doped Pt-CoO/Al 2 O 3 lead to the outstanding activity under the moisture-rich condition.