A5039639617- Electrocatalysts for Energy Conversion
- Fuel Cells and Related Materials
- Electrochemical Analysis and Applications
- Catalytic Processes in Materials Science
- Advanced battery technologies research
- Gold and Silver Nanoparticles Synthesis and Applications
- Advanced Battery Materials and Technologies
- CO2 Reduction Techniques and Catalysts
- Quantum Dots Synthesis And Properties
- Advancements in Battery Materials
- Machine Learning in Materials Science
- Advanced materials and composites
- Advanced Surface Polishing Techniques
- Nanocluster Synthesis and Applications
- 2D Materials and Applications
- Electronic and Structural Properties of Oxides
- Hybrid Renewable Energy Systems
- nanoparticles nucleation surface interactions
- Perovskite Materials and Applications
- Molten salt chemistry and electrochemical processes
- Electron and X-Ray Spectroscopy Techniques
- Copper-based nanomaterials and applications
- Ionic liquids properties and applications
- Advanced Battery Technologies Research
- X-ray Diffraction in Crystallography
Stanford University
2021-2025
SLAC National Accelerator Laboratory
2021-2025
Interface (United States)
2021-2025
University of California, Berkeley
2019-2022
University of California System
2019
Berkeley College
2019
Platinum is an important material with applications in oxygen and hydrogen electrocatalysis. To better understand how its activity can be modulated through electrolyte effects the double layer microenvironment, herein we investigate of different acid anions on platinum for reduction/evolution reaction (ORR/OER) evolution/oxidation (HER/HOR) pH 1 electrolytes. Experimentally, see ORR trend HClO
Metal–organic frameworks (MOFs) offer an interesting opportunity for catalysis, particularly metal–nitrogen–carbon (M–N–C) motifs by providing organized porous structural pattern and well-defined active sites the oxygen reduction reaction (ORR), a key need hydrogen fuel cells related sustainable energy technologies. In this work, we leverage electrochemical testing with computational models to study electronic properties in MOF systems their relationship ORR activity stability based on dual...
A significant challenge in commercializing electrochemical CO2 reduction (CO2R) is achieving catalyst durability. In this study, online inductively coupled mass spectrometry (ICP-MS) was used to investigate degradation via nanoparticle detachment and/or dissolution into metal ions under CO2R operating conditions 0.1 M KHCO3. We developed an experimental framework with ex situ characterization validate the ICP-MS method for evaluation of from foils. By varying applied potential and...
Cu nanocrystals as catalysts for CO2 reduction are a subject of considerable contemporary interest, but their stability has not been considered extensively. Herein, we report on the reconstruction during and discuss factors influencing observed changes with computer-based quantitative analysis spectroscopic techniques. The timelines opposing phenomena, sintering declustering, previously reported separately, detailed focus two forces affecting final morphology: applied potential reaction...
Abstract The local microenvironment at the electrode‐electrolyte interface plays an important role in electrocatalytic performance. Herein, we investigate effect of acid electrolyte anion identity on oxygen reduction reaction (ORR) activity and selectivity smooth Ag Pd catalyst thin films. Cyclic voltammetry perchloric, nitric, sulfuric, phosphoric, hydrochloric, hydrobromic acid, pH 1, reveals that ORR trends as follows: HClO 4 >HNO 3 >H 2 SO PO >HCl≫HBr, while as: >HCl≫HBr....
Diverse Ag–MnO x surface sites/structures in Ag–Mn electrocatalysts afford robust local electronic structures tuned for efficient oxygen reduction.
The size and shape of semiconductor nanocrystals govern their optical electronic properties. Liquid cell transmission electron microscopy (LCTEM) is an emerging tool that can directly visualize nanoscale chemical transformations therefore inform the precise synthesis nanostructures with desired functions. However, it remains difficult to controllably investigate reactions LCTEM, because highly reactive environment formed by radiolysis liquid. Here, we harness processes report single-particle...
An accelerated development of durable and affordable sustainable energy technologies is often hindered by a limited understanding how nonprecious materials within these systems degrade. In acidic proton exchange membrane fuel cells water electrolyzers, metallic cobalt (Co) considered an unstable component that combined with precious metals or other stabilizers. To understand the mechanisms behind Co instability, we employ experimental platform quantifies dissolution on-line inductively...
Accurately quantifying applied potential is important to ensuring the comparability, accuracy, and precision of electrochemical studies. Reference electrodes (REs) enable knowledge/determination at in systems. Ultimately, choice RE will depend on particular requirements a given system, however, we note it imperative ensure accuracy its proper translation standardized scale. In this work, highlight that while there are many commercially available REs, these must be experimentally calibrated...
Core-shell particles with thin noble metal shells represent an attractive material class potential for various applications ranging from catalysis to biomedical and pharmaceutical optical crystals. The synthesis of well-defined core-shell architectures remains, however, highly challenging. Here, we demonstrate that atomically-thin homogeneous platinum can be grown via a colloidal method on variety gold nanostructures spherical nanoparticles nanorods nanocubes. is based the exchange low...
Machine learning (ML) is gaining popularity as a tool for materials scientists to accelerate computation, automate data analysis, and predict properties. The representation of input material features critical the accuracy, interpretability, generalizability data-driven models scientific research. In this Perspective, we discuss few central challenges faced by ML practitioners in developing meaningful representations, including handling complexity real-world industry-relevant materials,...
Abstract Activation, break‐in, and/or pre‐treatment protocols are generally applied to energy conversion devices before regular operation reach stable performance. There remains much understand about the relationships among physical properties, performance, and electrochemical pre‐treatments. Here, a design‐of‐experiments (DoE) strategy is employed address this gap by demonstrating influence of five parameters for carbon‐supported Pt‐nanoparticle catalysts on electrocatalytic oxygen...
Natural photosynthesis relies on a sophisticated charge transfer pathway among multiple components with precise spatial, energetic, and temporal organizations in the aqueous environment. It continues to inspire challenge design fabrication of artificial multicomponent colloidal nanostructures for solar-to-fuel conversion. Herein, we introduce plasmonic photocatalyst synthesized methods five integrated including cocatalysts installed orthogonal locations. The deposition individual inorganic...
Improving electrocatalyst stability is critical for the development of electrocatalytic devices. Herein, we utilize an on-line electrochemical flow cell coupled with inductively plasma-mass spectrometer (ICP-MS) to characterize impact composition and reactant gas on multielement dissolution Mn(-Cr)-Sb-O electrocatalysts. Compared Mn2O3 Cr2O3 oxides, antimonate framework stabilizes Mn at OER potentials Cr both ORR potentials. Furthermore, from Mn(-Cr) -Sb-O driven by reaction rate, minimal...
The understanding of synthetic pathways bimetallic nanocrystals remains limited due to the complex energy landscapes and dynamics involved. In this work, we investigate formation self-limiting Cu@Ag core-shell nanoparticles starting from Cu followed by galvanic replacement with Ag ions. Bulk quantification atomic emission spectroscopy spatially resolved elemental mapping electron microscopy reveal distinct nucleation regimes that produce a tunable shell thickness, but only up certain...
The electrification of chemical processes provides a means to effectively utilize rapidly expanding renewable energy resources. Nonaqueous electrochemical systems offer promising opportunities, such as steering selectivity toward N2 reduction over the H2 evolution reaction. However, nonaqueous environments pose challenges for reference electrodes (REs), presenting need their design and development. In this study, we show utility Li0.5FePO4 (LFP) RE systems, demonstrating various desirable...
Perovskite nanoparticles have attracted the attention of research groups around world for their impressive photophysical properties, facile synthesis and versatile surface chemistry. Here, we report a synthetic route that takes advantage suite soluble precursors to generate CsPbBr3 perovskite nanoplatelets with fine control over size, thickness optical properties. We demonstrate near unit cell precision, creating well characterized materials sharp, narrow emission lines at 430, 460 490 nm...
Abstract Computationally predicting the performance of catalysts under reaction conditions is a challenging task due to complexity catalytic surfaces and their evolution in situ, different paths, presence solid‐liquid interfaces case electrochemistry. We demonstrate here how relatively simple machine learning models can be found that enable prediction experimentally observed onset potentials. Inputs our model are comprised data from oxygen reduction on non‐precious transition‐metal antimony...
Electrocatalysts enable the efficient conversion of molecules for applications in energy devices, but due to their material stability, electrochemical performance tends change over time under operating conditions. For oxygen reduction reaction (ORR), transition metal x-ides (oxides, nitrides, sulfides) are a class highly tunable, low-cost catalysts being considered as possible alternatives expensive Pt-based materials. In this work, we take multimodal characterization approach investigate...
Sustainable electricity generation via hydrogen fuel cells requires the development of efficient oxygen reduction reaction (ORR) catalysts. In situ/operando experiments are necessary to uncover extent dynamic material changes during catalysis. Herein, we use in X-ray absorption near-edge spectroscopy track Mn valence a promising, ultrathin, porous MnOx layer on Ag thin film. Mn–K-edge measurements as function electrochemical environment and ORR conditions reveal that, interestingly, when...
Platinum (Pt) plays a key role as an electrocatalyst in renewable electrochemical energy technologies such fuel cells and electrolyzers. Better understanding the interfacial phenomena at Pt-electrolyte interface can help guide microenvironment engineering to tune performance via electrolyte effects. Herein, we investigate effect of electrolyte, more specifically anion, identity on activity Pt for oxygen reduction reaction (ORR), evolution (OER), hydrogen (HER), oxidation (HOR) pH 1. In...