Abstract
Palladium nanoparticles have been studied extensively as catalysts for the direct synthesis of hydrogen peroxide, where selectivity remains a key challenge. Alloying Pd with other metals and using acid and halide promoters are commonly employed to increase H2O2 selectivity; however, the sites that can selectively produce H2O2 have not been identified and the role of these additives remains unclear. Here, we report the synthesis of atomically dispersed PdClx/C as a model catalyst for H2O2 production without the presence of extended Pd surfaces. We show that these isolated cationic Pd sites can form H2O2 with significantly higher selectivity than metallic Pd nanoparticles in both the reaction of H2 and O2 and the electrochemical oxygen reduction reaction. These results demonstrate that catalysts containing high populations of isolated Pd sites are selective catalysts for this two-electron reduction reaction and that the performance of materials in the direct synthesis reaction and electrocatalytic oxygen reduction reaction has many similarities.
Original language | English |
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Pages (from-to) | 5928-5938 |
Number of pages | 11 |
Journal | ACS Catalysis |
Volume | 10 |
Issue number | 10 |
Early online date | 23 Apr 2020 |
DOIs | |
Publication status | Published - 15 May 2020 |
Funding
M.L. acknowledges the Federal Ministry of Education and Research (BMBF) in the framework of NanoMatFutur (SynKat, FK: 03XP0265) for financial support. K.J.J.M. acknowledges the Federal Ministry for Economic Affairs and Energy (BMWi) of Germany in the framework of PtTM@HGS (project number 03ET6080A). E.P. acknowledges the financial support from the IMPRS-SurMat doctoral program. We thank Andrea Mingers for help with ICP-MS, Alexander Auer and Corentin Poidevin for fruitful discussions, and the MAXNET Energy and Cardiff University for the financial support of the project. S.J.F. acknowledges the University of Bath for the award of a Prize Research Fellowship in Sustainable Technology. The authors thank the UK Catalysis Hub for allocating beamtime through the UK Catalysis Hub BAG for X-ray acquisition of the absorption spectroscopic data at the Diamond synchrotron facility (SP15151).
Keywords
- catalysis
- electrocatalysis
- hydrogen peroxide
- palladium
ASJC Scopus subject areas
- Catalysis
- General Chemistry