EW

E.E. Westsson

info

Please Note

3 records found

Journal article (2020) - Emma Westsson, Stephen Picken, Ger Koper
Magnetic field effects can provide a handle on steering chemical reactions and manipulating yields. The presence of a magnetic field can influence the energy levels of the active species by interacting with their spin states. Here we demonstrate the effect of a magnetic field on the electrocatalytic processes taking place on platinum-based nanoparticles in fuel cell conditions. We have identified a shift in the potentials representing hydrogen adsorption and desorption, present in all measurements recorded in the presence of a magnetic field. We argue that the changes in electrochemical behavior are a result of the interactions between the magnetic field and the unpaired spin states of hydrogen. ...
Doctoral thesis (2019) - Emma Westsson, Ger Koper, Stephen Picken
The increasing energy demand of the world population in combination with tangible climate change effects stemming from rising carbon dioxide emissions is currently characterizing a large portion of the political and societal debate. Despite huge technological advancement in the field of renewable energy resulting in energy prices lower than that of fossil based energy, the rate of greenhouse gas emissions has not even levelled off but rather kept increasing. A part of the problem lies in the very nature of season and weather dependent energy conversion technologies producing electricity peaks that are hard to buffer. The solar and wind powered scenario is not yet able to completely replace the relatively demand flexible fossil fuel based power plants. The gap between energy production and energy use, in essence meaning storage and distribution of sustainable energy, constitutes one of the largest challenges of our times. Hydrogen has been proposed as a molecule with the potential of being an important energy carrier in a renewable energy based economy. In a fuel cell, hydrogen can be electrochemically oxidized to water, releasing its chemical energy without the emission of combustion by-products like carbon dioxide. Commonly platinum is used as a catalyst to speed up the anode and cathode reactions in a fuel cell. Reversibly, an electrolyser uses electricity to electrochemically split water into its constituents; hydrogen and oxygen. Ideally, hydrogen could be produced where and when the electricity is available or cheap and be stored or transported to the location where it is needed, although technical challenges as well as infrastructural hurdles are still to be solved. If electrochemical devices, such as fuel cells, are to play a major role in the future energy landscape a better understanding of catalytic processes along with cheap and scalable non-noble metal catalysts are still needed. ...
Journal article (2019) - Emma Westsson, Stephen Picken, Ger Koper
We report on the effect of lattice strain in three different types of core-shell electrocatalyst particles on their catalytic activity towards the oxygen reduction reaction. We decouple the changes in catalytic activity with respect to a geometrical and an energetic contribution, both of electronic origin. ...