Outstanding Methane Oxidation Performance of Palladium-Embedded Ceria Catalysts Prepared by a One-Step Dry Ball-Milling Method

Maila Danielis; Sara Colussi; Carla de Leitenburg; Lluís Soler; Jordi Llorca; Alessandro Trovarelli

doi:10.1002/anie.201805929

Outstanding Methane Oxidation Performance of Palladium-Embedded Ceria Catalysts Prepared by a One-Step Dry Ball-Milling Method

Angew Chem Int Ed Engl. 2018 Aug 6;57(32):10212-10216. doi: 10.1002/anie.201805929. Epub 2018 Jul 6.

Authors

Maila Danielis¹, Sara Colussi¹, Carla de Leitenburg¹, Lluís Soler², Jordi Llorca², Alessandro Trovarelli¹

Affiliations

¹ Polytechnic Department, University of Udine, Via del Cotonificio 108, 33100, Udine, Italy.
² Institute of Energy Technologies, Department of Chemical Engineering and Barcelona Research Centre in Multiscale Science and Engineering, Universitat Politècnica de Catalunya, EEBE, Eduard Maristany 10-14, 08019, Barcelona, Spain.

PMID: 29924472
DOI: 10.1002/anie.201805929

Abstract

By carefully mixing Pd metal nanoparticles with CeO₂ polycrystalline powder under dry conditions, an unpredicted arrangement of the Pd-O-Ce interface is obtained in which an amorphous shell containing palladium species dissolved in ceria is covering a core of CeO₂ particles. The robust contact that is generated at the nanoscale, along with mechanical forces generated during mixing, promotes the redox exchange between Pd and CeO₂ and creates highly reactive and stable sites constituted by PdO_x embedded into CeO₂ surface layers. This specific arrangement outperforms conventional Pd/CeO₂ reference catalysts in methane oxidation by lowering light-off temperature by more than 50°C and boosting the reaction rate. The origin of the outstanding activity is traced to the structural properties of the interface, modified at the nanoscale by mechanochemical interaction.

Keywords: ceria; combustion; mechanochemistry; methane; palladium.