10.1021/jz5009483.s001 Cristihan Carrillo Cristihan Carrillo Tyne R. Johns Tyne R. Johns Haifeng Xiong Haifeng Xiong Andrew DeLaRiva Andrew DeLaRiva Sivakumar R. Challa Sivakumar R. Challa Ronald S. Goeke Ronald S. Goeke Kateryna Artyushkova Kateryna Artyushkova Wei Li Wei Li Chang H. Kim Chang H. Kim Abhaya K. Datye Abhaya K. Datye Trapping of Mobile Pt Species by PdO Nanoparticles under Oxidizing Conditions American Chemical Society 2015 diesel exhaust catalysis catalyst Mobile Pt Species PdO oxidizing conditions 2015-12-17 02:43:28 Journal contribution https://acs.figshare.com/articles/journal_contribution/Trapping_of_Mobile_Pt_Species_by_PdO_Nanoparticles_under_Oxidizing_Conditions/2034828 Pt is an active catalyst for diesel exhaust catalysis but is known to sinter and form large particles under oxidizing conditions. Pd is added to improve the performance of the Pt catalysts. To investigate the role of Pd, we introduced metallic Pt nanoparticles via physical vapor deposition to a sample containing PdO nanoparticles. When the catalyst was aged in air, the Pt particles disappeared, and the Pt was captured by the PdO, forming bimetallic Pt–Pd nanoparticles. The formation of metallic Pt–Pd alloys under oxidizing conditions is indeed remarkable but is consistent with bulk thermodynamics. The results show that mobile Pt species are effectively trapped by PdO, representing a novel mechanism by which Ostwald ripening is slowed down. The results have implications for the development of sinter-resistant catalysts and help explain the improved performance and durability of Pt–Pd in automotive exhaust catalytic converters.