A5080975410- Electrocatalysts for Energy Conversion
- Electrochemical Analysis and Applications
- Catalytic Processes in Materials Science
- Corrosion Behavior and Inhibition
- Advanced battery technologies research
- Dendrimers and Hyperbranched Polymers
- Hydrogen Storage and Materials
- Fuel Cells and Related Materials
- Semiconductor materials and devices
- Copper-based nanomaterials and applications
- Machine Learning in Materials Science
- Gas Sensing Nanomaterials and Sensors
- Catalysis for Biomass Conversion
- Electron and X-Ray Spectroscopy Techniques
- Hybrid Renewable Energy Systems
- Chemical and Physical Properties of Materials
- Surface and Thin Film Phenomena
- Advanced Photocatalysis Techniques
- Radioactive element chemistry and processing
- Nanocluster Synthesis and Applications
- Gold and Silver Nanoparticles Synthesis and Applications
- Nanomaterials for catalytic reactions
- CO2 Reduction Techniques and Catalysts
- Health and Medical Research Impacts
- Molecular Junctions and Nanostructures
Leiden University
2014-2025
SLAC National Accelerator Laboratory
2020-2025
Stanford Synchrotron Radiation Lightsource
2020-2025
Menlo School
2023
The University of Texas at Austin
2021-2022
Stanford University
2015
Developing improved catalysts for the oxygen evolution reaction (OER) is key to advancement of a number renewable energy technologies, including solar fuels production and metal air batteries. In this study, we employ electrochemical methods synchrotron techniques systematically investigate interactions between oxides noble metals that lead enhanced OER catalysis water oxidation. particular, synthesize porous MnOx films together with nanoparticles Au, Pd, Pt, or Ag observe significant...
Electrolysis coupled with renewable energy is essential for green hydrogen production and its application to achieving deep decarbonization. The efficiency of electrolysis limited by the oxygen evolution reaction (OER), which requires an efficient, low-cost, acid-stable catalyst proton exchange membrane (PEM) electrolysis. In this work, we designed a highly active, involving iridium-tungsten trioxide (Ir:WO3/Ir). Our theory predicts that high-valence Ir atoms are active sites OER they can be...
We present a systematic electrochemical and spectroelectrochemical study of the catalytic activity for water oxidation an iridium-N-dimethylimidazolin-2-ylidene (Ir-NHC-Me2) complex adsorbed on polycrystalline gold electrode. The work aims to understand effect electrolyte properties (anions acidity) molecular catalyst check its stability toward decomposition. Our results show that iridium displays very strong dependence such large enhancements in may be obtained by adequately choosing pH...
Cathodic corrosion is a process that etches metal electrodes under cathodic polarization. This presumed to occur through anionic metallic reaction intermediates, but the exact nature of these intermediates and onset potential their formation unknown. Here we determine on platinum electrodes. Electrodes are characterized electrochemically before after polarization in 10 M sodium hydroxide, revealing changes electrode surface start at an -1.3 V versus normal hydrogen electrode. The value this...
Cathodic corrosion is an electrochemical etching process that alters metallic surfaces by creating nanoparticles and a variety of features. Because these features typically have preferential orientation, cathodic can be applied to modify nanostructure electrode surfaces. However, this application currently limited insufficient chemical understanding its underlying mechanism. This includes the role alkali metal cations, which are thought crucial in both enabling controlling final facet...
Cathodic corrosion is an enigmatic electrochemical process that etches metallic electrodes at potentials below 0 V versus the normal hydrogen electrode. Although this phenomenon was discovered in late 1800s by Fritz Haber, it remained mostly unnoticed during 20th century and only attracted increased attention past decade. This recent has generated marked improvements both fundamental knowledge applications of cathodic corrosion. Fundamental new insights were gained into effects possible...
Developing active and selective electrocatalysts is of prime importance in shifting society toward utilizing renewable energy sources. Such developments often require catalysts with particular morphologies because many chemical reactions are sensitive to the catalyst structure. However, it can be challenging synthesize stabilize shape-controlled catalysts. It would therefore desirable tailor morphology an existing electrocatalyst exhibit favorable catalytic properties. In this work, such...
We present evidence that the “third hydrogen peak” involves surface-adsorbed on a locally “reconstructed” (110)-type surface site.
Significance Cathodic corrosion is a relatively unexplored but highly enigmatic electrochemical phenomenon that transforms, roughens, and dissolves metal surfaces under cathodic polarization. We show how of platinum spherical single-crystal electrode in an aqueous alkaline electrolyte leads initially to the formation etch pits reflect local symmetry surface subsequently develop into growth regime which self-similar diffusion-limited patterns emerge. These are unique observations may...
In the pursuit of a hydrogen economy, extensive research has been directed at developing acidic and alkaline fuel cells. Such cells often utilize platinum-based catalysts. These materials have studied extensively in conditions but not ones. This focus on systems creates marked knowledge gap, since recent studies indicate that carbon-supported platinum (Pt/C) electrocatalysts degrade more rapidly bases than acids. Addressing this present work investigates Pt/C degradation pH 2 12 using...
Support effects in supported metal catalysts are well studied for thermocatalytic reactions, but less electrocatalytic reactions. Here, we prepared a series of Pt on carbon nanofiber which vary their particle size and the content oxygen groups surface CNF. We show that activity these glucose oxidation relates linearly with support groups. Since electronic state (XAS) structure (CO-stripping) were indistinguishable all materials, conclude sorption play crucial role catalytic activity. This...
Cathodic corrosion is a phenomenon in which negatively polarized metal electrodes are degraded by cathodic etching and nanoparticle formation. Though these changes dramatic sometimes even visible eye, the exact mechanisms underlying still unclear. This work aims to improve understanding of studying its onset on rhodium gold electrodes, subjected various constant potentials 10 M NaOH. After this polarization, studied using cyclic voltammetry scanning electron microscopy, allowing potential...
Sushanta Mitra opened a general discussion of the paper by Keith Stevenson: For nanoparticle impact study, if there are surface charges present on nanoparticle, will be any screening effect? The reason for such an issue is that often they modeled as particle-collector (Happel
When preparing alloy nanoparticles through cathodic corrosion, the different corrosion behavior of components may produce both crystalline and amorphous particles.
Abstract Here we show that just three electrochemical scans to modest positive potentials result in substantial growth of 1–2 nm Au dendrimer‐encapsulated nanoparticles (DENs). We examined two sizes DENs, denoted as G6‐NH 2 (Au 147 ) and 55 ), where represents a sixth‐generation, amine‐terminated, poly(amidoamine) dendrimer the subscripts, 55, represent average number atoms each size DENs. Ex situ transmission electron microscopy (TEM) X‐ray absorption spectroscopy (XAS) results indicate...
Photocatalysis is a promising concept for the direct conversion of solar energy into fuels and chemicals. The design, experimental protocol, performance multimodal versatile flow reactor characterization powdered immobilized photocatalysts are herein presented. Ultimately, this instrument enables rigorous evaluation photocatalysis metrics. apparatus quantifies transient gas-phase reaction products via online real-time gas analyzer mass spectrometry (RTGA-MS). For H2, most challenging gas,...
Yitao Long opened the discussion of paper by Lei Jiang:This was not presented; questions on this were communicated after meeting. This work is a very good example your recently proposed 'quantum-confined superfluid' concept – it really imperative to fabricate ion chann
Water electrolysis powered by renewable energy is a promising technology which can produce green H 2 with no direct CO emissions. The US Department of Energy has set an ambitious target to bring down the cost $1 per kg within next decade. To drive innovation required meet this target, it essential we understand catalyst behavior in realistic zero gap membrane based electrolyzers operating at industrially relevant current densities. Towards goal, have developed methodologies for conducting...
Richard Nichols opened a general discussion of the paper by Olaf Magnussen: You state that perchlorate is not absorbed on bismuth. What evidence for this? For example this apparent from voltammetry? Magnussen answered: Previous studies Bi UPD Au(111) and
Dendrimers are branched macromolecules that can be functionalized with a large variety of chemical moieties. therefore specifically designed to interact target molecules. Although tailored dendrimers hold promise for targeted drug delivery and wastewater cleanup, these applications require more detailed systematic studies on how dendrimer-guest interactions depend environmental conditions. In light this need, we studied pH-dependent between fluorescein poly(amidoamine) three different...
Support effects in supported metal catalysts are well studied for thermocatalytic reactions, but less electrocatalytic reactions. Here, we prepared a series of Pt on carbon nanofiber which vary their particle size and the content oxygen groups surface CNF. We show that activity these glucose oxidation relates linearly with support groups. Since electronic state (XAS) structure (CO-stripping) were indistinguishable all materials, conclude sorption play crucial role catalytic activity. This...
Julie MacPherson opened discussion of the paper by Richard M. Crooks: What happens if you apply a continuous potential, as opposed to pulsed in terms morphology Pt deposit? Why did choose such high frequency; what's rationale behind this? For frequencies