Engineering topics
Rossmeisl, Jan
Publications and source records attributed to Rossmeisl, Jan.
Enhanced Carbon Dioxide Electroreduction to Carbon Monoxide over Defect-Rich Plasma-Activated Silver Catalysts
Efficient, stable catalysts with high selectivity for a single product are essential if electroreduction of CO 2 is to become a viable route to the synthesis of industrial feedstocks and fuels. A plasma oxidation pre-treatment of silver foil enhances the number of low-coordinated catalytically active sites, which dramatically lowers the overpotential and increases the activity of CO 2 electroreduction to CO. At -0.6 V versus RHE more than 90 % Faradaic efficiency towards CO was achieved on a pre-oxidized silver foil. While transmission electron microscopy (TEM) and operando X-ray absorption spectroscopy showed that oxygen species can survive in the bulk of the catalyst during the reaction, quasi in situ X-ray photoelectron spectroscopy showed that the surface is metallic under reaction conditions. Finally, DFT calculations reveal that the defect-rich surface of the plasma-oxidized silver foils in the presence of local electric fields drastically decrease the overpotential of CO 2 electroreduction.
Orientation-Dependent Oxygen Evolution on RuO 2 without Lattice Exchange
RuO2 catalysts exhibit record activities towards the oxygen evolution reaction (OER), which is crucial to enable efficient and sustainable energy storage. Here we examine the RuO2 OER kinetics on rutile (110), (100), (101), and (111) orientations, finding (100) the most active. We assess the potential involvement of lattice oxygen in the OER mechanism with online 3 electrochemical mass spectrometry, which showed no evidence of oxygen exchange on these oriented facets in acidic or basic electrolytes. Similar results were obtained for polyoriented RuO2 films and particles, in contrast to previous work, suggesting lattice oxygen is not exchanged in catalyzing OER on crystalline RuO2 surfaces. This hypothesis is supported by the correlation of activity with the number of active Ru-sites calculated by DFT, where more active facets bind oxygen more weakly. This new understanding of the active sites provides a design strategy to enhance the OER activity of RuO2 nanoparticles by facet engineering.
Probing the nanoscale structure of the catalytically active overlayer on Pt alloys with rare earths
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Water at Interfaces
The interfaces of neat water and aqueous solutions play a prominent role in many technological processes and in the environment. Examples of aqueous interfaces are ultrathin water films that cover most hydrophilic surfaces under ambient relative humidities, the liquid/solid interface which drives many electrochemical reactions, and the liquid/vapor interface, which governs the uptake and release of trace gases by the oceans and cloud droplets. In this work, we review some of the recent experimental and theoretical advances in our knowledge of the properties of aqueous interfaces and discuss open questions and gaps in our understanding.
On the pH dependence of electrochemical proton transfer barriers
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Mechanistic Pathway in the Electrochemical Reduction of CO 2 on RuO 2
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Ketene as a Reaction Intermediate in the Carbonylation of Dimethyl Ether to Methyl Acetate over Mordenite
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The Influence of Particle Shape and Size on the Activity of Platinum Nanoparticles for Oxygen Reduction Reaction: A Density Functional Theory Study
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