Atomically dispersed Pt-N-4 sites as efficient and selective electrocatalysts for the chlorine evolution reaction

Chlorine evolution reaction (CER) is a critical anode reaction in chlor-alkali electrolysis. Although precious metal-based mixed metal oxides (MMOs) have been widely used as CER catalysts, they suffer from the concomitant generation of oxygen during the CER. Herein, we demonstrate that atomically dispersed Pt-N-4 sites doped on a carbon nanotube (Pt-1/CNT) can catalyse the CER with excellent activity and selectivity. The Pt-1/CNT catalyst shows superior CER activity to a Pt nanoparticle-based catalyst and a commercial Ru/Ir-based MMO catalyst. Notably, Pt-1/CNT exhibits near 100% CER selectivity even in acidic media, with low Cl- concentrations (0.1M), as well as in neutral media, whereas the MMO catalyst shows substantially lower CER selectivity. In situ electrochemical X-ray absorption spectroscopy reveals the direct adsorption of Cl- on Pt-N-4 sites during the CER. Density functional theory calculations suggest the PtN4C12 site as the most plausible active site structure for the CER

The Role of TiO2 Doping on RuO2-Coated Electrodes for the Water Oxidation Reaction

Electrochemical water splitting into H2 and O2 presents a significant and challenging energy loss due to the high overpotential required at the anode. Today, in industrially relevant applications, dimensionally stable anodes (DSA) based on the electrocatalytic active RuO2 are conventionally utilized. To enhance the resistance against corrosion, incorporation of TiO2 in the RuO2-coated electrodes is widely employed. In the present work we have used scanning electrochemical microscopy (SECM) to demonstrate that TiO2-doped RuO2-coated electrodes, in addition to being more durable, also show an electrocatalytic activity that is, on average, 13% higher as compared to the pure RuO2-coated electrodes. We also demonstrate that cracks in the pure RuO2 coating are the most active zones, probably because Ti from the Ti support has diffused into the first applied layer of the RuO2 coating. To reveal the nature of this enhanced activity for water oxidation displayed on TiO2-doped RuO2 electrodes, we have employed X-ray photoelectron spectroscopy (XPS) for material characterization. The results show that the electrocatalytic activity enhancement displayed on the mixed (Ru1–x:Tix)O2 coating is promoted through a charge transfer from the RuO2 to the TiO2, which provides new and more reactive sites designated as activated RuO2δ+.This study has partly been carried out in the framework of the European Commission FP7 Initial Training Network “ELCAT”, Grant Agreement No. 214936-2. Portions of this research were performed at SPring-8 with the approval of Japan Synchrotron Radiation Research Institute as Nanotechnology Support Project of the Ministry of Education, Culture, Sports, Science and Technology (Proposal No. 2007A2005 and 2008A1671/BL-47XU)

Local Structure of Pulse Plated Ni Rich Ni-Zn Alloys and Its Effect on the Electrocatalytic Activity in the Hydrogen Evolution Reaction

This open-label extension evaluated the long-term efficacy and tolerability of rufinamide in patients with Lennox-Gastaut syndrome (LGS) who had previously completed a 12-week double-blind study.In total, 124 patients (aged 4-37 years), receiving 1-3 concomitant antiepileptic drugs, were treated with rufinamide approximately 25-60 mg/kg/day. Efficacy was assessed by seizure frequency; tolerability by adverse events (AEs) and laboratory tests.Overall, patients were treated with rufinamide for a median (range) of 432 (10-1149) days. Reductions in seizure frequency were observed throughout the study; during the last 12 months of treatment, 41.0% and 47.9% of patients had > or = 50% reduction in total and tonic-atonic seizure frequency, respectively. The most common AEs were vomiting (30.6%) and pyrexia (25.8%).In this open-label extension, rufinamide appeared to be an effective long-term adjunctive therapy for the treatment of LGS-associated seizures in children and young adults

In-field performance and flux pinning mechanism of pulsed laser deposition grown BaSnO 3 /GdBa 2 Cu 3 O 7- δ nanocomposite coated conductors by SuperOx

We investigate the field, angle and temperature dependence of the full-width critical current, I-c, of pulsed laser deposition-grown GdBa2Cu3O7 coated conductors with and without additional 6 mol% BaSnO3 (BSO) nanoparticles fabricated by SuperOx. The transport characteristics measured from 7 to 77 K and in applied magnetic fields of up to 6 T are complemented by scanning transmission electron microscopy. This combined approach allows for further insight into the vortex pinning mechanism and helps with understanding the enhancement in I-c. An exemplary scaling of the pinning force curves versus field at different temperatures confirms the additional contribution to pinning by the BSO nanoparticles. Through the temperature dependence of I-c, the weak and strong pinning contributions are determined: strong pinning dominates over almost the entire temperature range especially near the matching field of 1 T, where the largest enhancement in I-c is achieved