Search Results

You searched for all publications:

with publication states 'Published (Approved)'

Search Again...

These results only include publications that have been reviewed and processed by Diamond Light Source. To also view papers that have not yet been processed click here.

You can use the folder icon under Actions to collate papers as required. You can then click on View Folder in the left-hand navigation to review and/or download your folder.

Exact matches
Related results

3 items found (0 items not approved), displaying all items.1

Instruments / Technical Area	Publication Details	Published
B07-B-Versatile Soft X-ray beamline: High Throughput	Enhanced stability of SrRuO3 mixed oxide via monovalent doping in Sr1-xKxRuO3 for the oxygen evolution reaction Isabel Rodríguez-García , Dmitry Galyamin , Laura Pascual , Pilar Ferrer , Miguel A. Peña , David Grinter , Georg Held , Mohamed Abdel Salam , Mohamed Mokhtar , Katabathini Narasimharao , Maria Retuerto , Sergio Rojas Journal Of Power Sources 521 DOI: 10.1016/j.jpowsour.2021.230950 Diamond Proposal Number(s): [28150] Open Access Show Abstract ▼ Abstract: Ru mixed oxides are the most active catalysts for the oxygen evolution reaction (OER) in acid electrolyte. However, their stability is seriously compromised during the reaction. In this work we show that it is possible to enhance both OER activity and durability of SrRuO3 mixed oxide by the partial doping with K+ in Sr2+ sites. Sr1-xKxRuO3 perovskites (x = 0.00, 0.05, 0.10 and 0.20) have been synthesized by wet chemistry. The partial doping with K+ cations led to oxides with Ru atoms in a higher oxidation state. In addition, K-doping resulted in perovskites with slightly higher symmetry. The performance of the K-doped perovskites for the OER was assessed in acid electrolyte. Clearly, the K-doped materials, especially Sr0.80K0.20RuO3, display higher activity (lower E10) and significantly higher durability than the undoped sample SrRuO3. The results indicate that chemical modifications on Ru perovskites can be a suitable strategy to improve the stability of Ru phases during the OER.	Feb 2022
B18-Core EXAFS	Effect of the thermal treatment of Fe/N/C catalysts for the oxygen reduction reaction synthesized by pyrolysis of covalent organic frameworks Álvaro García , Tarrick Haynes , Maria Retuerto , Pilar Ferrer , Laura Pascual , Miguel A. Peña , Mohamed Abdel Salam , Mohamed Mokhtar , Diego Gianolio , Sergio Rojas Industrial & Engineering Chemistry Research DOI: 10.1021/acs.iecr.1c02841 Diamond Proposal Number(s): [24881] Open Access Show Abstract ▼ Abstract: A nitrogen-containing covalent organic framework obtained from the polymerization of 1,3-dicyanobenzene has been used as a starting material for the synthesis of Fe/N/C catalysts for the oxygen reduction reaction (ORR). In this work we report the effect of the thermal treatments on the nature and catalytic properties of the catalysts obtained after the thermal treatments. After the first thermal treatment, the catalysts obtained contain metallic iron and iron carbide particles, along with a minority fraction of inorganic FeNx sites. After acid leaching and a second thermal treatment, FeNx sites remain in the catalysts, along with a minor fraction of graphite-wrapped Fe3C particles. Both catalysts display high activity for the ORR, with the catalyst subjected to acid leaching and a second thermal treatment, 2HT-1,3DCB, displaying higher ORR activity and a lower production of H2O2. This observation suggests that iron particles, such as Fe3C, display ORR activity but mainly toward the two-electron pathway. On the contrary, FeNx ensembles promote the ORR via the four-electron pathway, that is, via H2O formation.	Nov 2021
B07-C-Versatile Soft X-ray beamline: Ambient Pressure XPS and NEXAFS B18-Core EXAFS	Study of the evolution of FeNxCy and Fe3C species in Fe/N/C catalysts during the oxygen reduction reaction in acid and alkaline electrolyte Álvaro García , Laura Pascual , Pilar Ferrer , Diego Gianolio , Georg Held , David C. Grinter , Miguel A. Peña , Maria Retuerto , Sergio Rojas Journal Of Power Sources 490 DOI: 10.1016/j.jpowsour.2021.229487 Diamond Proposal Number(s): [26554] Open Access Show Abstract ▼ Abstract: The nature and evolution of FeNxCy moieties in Fe/C/N catalysts has been studied by analysing Fe and N environments. TEM and Fe-XAS reveal the presence of FeNx moieties and Fe3C particles in the fresh catalyst. NEXAFS reveals the presence of two groups of (Fe)NxCy ensembles, namely (Fe)Nx-pyridinic and (Fe)Nx-pyrrolic. The architecture of the FeNxCy ensembles and their evolution during the ORR has been analysed by XAS, NEXAFS, and identical locations TEM. NxCy, FeNxCy and Fe3C species are partially removed during the ORR, resulting in the formation of Fe2O3 and Fe3O4 particles with different morphologies. The process is more severe in acid electrolyte than in alkaline one. (Fe)Nx-pyrrolic moieties are the main ones in the fresh catalysts, but (Fe)Nx-pyridinic groups are more stable after the ORR. The correlation between the evolution of the ORR activity and that of the FeNxCy ensembles indicates that FeNx-pyridinic ensembles are responsible for the ORR activity.	Apr 2021

Publications Database

Search Results

You searched for all publications:

Search Again...

Subject Areas (check all that apply) select all

Instruments used to collect data (check all that apply) select all

Collaborations involved (check all that apply) select all

Diamond Offline Facilities used

Relevant Technical Areas (check all that apply) select all

Menu for Anonymous User