Decarbonization of the energy system across different sectors using power-to-X concepts relies heavily on the availability of low-cost hydrogen produced from renewable power by water electrolysis. Polymer electrolyte water electrolysis (PEWE) is a promising technology for hydrogen (and oxygen) production for distributed as a well as centralized operation. The total cost of hydrogen is dominated by the electricity cost. Therefore, increase of conversion efficiency is pivotal in improving the commercial viability of electrolytically produced hydrogen. In this study, we investigate the prospects of improving conversion efficiency by reducing the membrane thickness from 200 to 50 micron and increasing the cell temperature from 60 to 120°C.
The interplay between oxygen and spin ordering for the low oxygen doped Nd2NiO4.10 has been investigated by single-crystal neutron diffraction. We find a coexistence of the magnetic order below TN with the 3D ordering of excess oxygen atoms, which has not been previously observed for the homologous nickelates. Moreover, the magnetic ordering modulation vectors are no longer independent and exactly follow the modulation vectors of the oxygen ordering.
Results are reported on BS0 →μ+μ- decays using 61 fb-1 of proton-proton collision data obtained in 2011-2016 with the CMS experiment at the LHC (CERN). In the standard model (SM) of particle physics this decay can be precisely calculated with small theoretical uncertainties, making it an excellent probe for testing the limits of the SM. The branching fraction BF(BS0 →μ+μ-)=(2.9 ± 0.7) x 10-9 is measured with a statistical significance of 5.6 standard deviations. In addition, the effective lifetime of this decay is measured as 𝜏𝜇𝜇=1.70+0.61−0.44
ps. Both results are in good agreement with the SM prediction. In comparison to the previous analysis, a much improved muon identification algorithm significantly increased the purity and strongly reduced the background. As a consequence, the measurement of BF(B0 →μ+μ-) < 3.6 x 10-10 at 95% CL is no longer in tension to the SM, but fully compatible with it.
Silicon is a long-standing candidate for replacing graphite as the active material in negative electrodes for Li-ion batteries, due to its significantly higher specific capacity. However, Si suffers from rapid capacity loss, as a result of the large volume expansion and contraction during lithation and de-lithiation. As an alternative to pure Si electrodes, Si could be used as a capacity-enhancing additive to graphite electrodes.
In December 2020, the Swiss Academy of Sciences (SCNAT) published its white book on radiochemical education in Switzerland. The report was authored under the lead of Prof. Dr. Roger Alberto (University of Zurich), Dr. Mario Burgener (Spiez Laboratory), and Prof. em. Dr. Heinz W. Gäggeler (University of Bern/Paul Scherrer Institute) and comprises contributions from many experts on the topic from various institutions throughout Switzerland. The white book highlights the imminent loss of experts in the field of radiochemistry and provides solutions to counteract this development.
As of December 10, 2020, the ETH Zurich appointed PSI’s Prof. Dr. Patrick Steinegger as assistant professor of radiochemistry (tenure track). Thus, the ETH domain took first counter measures against the imminent loss of radiochemical expertise in Switzerland, emphasized in the “Weissbuch Radiochemie Schweiz” by the Swiss Academy of Sciences (SCNAT). Furthermore, the December issue of CHIMIA (Swiss Chemical Society) invited to present the diverse radiochemical activities throughout the country.
Ultrafast long-range coherent dynamics in electronic structure excited by THz pulses and studied using free electron laser based resonant X-ray diffraction.
Synthesis book reviews history, milestones and achievements of the center
Oxygen Evolution Reaction Activity and Underlying Mechanism of Perovskite Electrocatalysts at Different pH
PSI researchers have studied the how the electrolyte pH values influence the oxygen evolution reaction (OER) activity and stability of different promising perovskite oxide catalysts for application as anodic electrodes in alkaline water electrolyzers. The OER activity and stability decreased decreasing the electrolyte pH values. By combining electrochemical studies and operando X-ray absorption spectroscopy measurements, it has been suggested that different reaction mechanisms dominate in alkaline and near-neutral electrolyte pH region.
Key activity descriptors of nickel-iron oxygen evolution electrocatalysts in the presence of alkali metal cations
Ni-Fe oxyhydroxide is among the most active oxygen evolution electrocatalysts. Electrolyte alkali metal cations modify the activity and reaction intermediates, however, the exact mechanism is at question due to unexplained deviations from the cation size trend. Our X-ray absorption spectroelectrochemical results show that the OER activity follows the variations in .electrolyte pH rather than a specific cation. Our DFT-based reactivity descriptors confirm the conclusions of an indirect pH effect.