A5045070002- Catalytic Processes in Materials Science
- Catalysis and Oxidation Reactions
- Electrocatalysts for Energy Conversion
- Nanomaterials for catalytic reactions
- Copper-based nanomaterials and applications
- Catalysts for Methane Reforming
- Advanced Photocatalysis Techniques
- Quantum Dots Synthesis And Properties
- Covalent Organic Framework Applications
- Surgical Simulation and Training
- CO2 Reduction Techniques and Catalysts
- Cardiac, Anesthesia and Surgical Outcomes
- Gold and Silver Nanoparticles Synthesis and Applications
- Simulation-Based Education in Healthcare
- Catalysis for Biomass Conversion
- Anatomy and Medical Technology
- Asymmetric Synthesis and Catalysis
- Catalysis and Hydrodesulfurization Studies
- nanoparticles nucleation surface interactions
- Metal-Organic Frameworks: Synthesis and Applications
- Nanocluster Synthesis and Applications
- Health Literacy and Information Accessibility
- Recycling and utilization of industrial and municipal waste in materials production
- Industrial Gas Emission Control
- Architecture and Computational Design
Stanford University
2016-2023
Interface (United States)
2017-2022
Beth Israel Deaconess Medical Center
2022
Stanford Medicine
2020
California Institute of Technology
2014-2015
CO2 reduction to higher value products is a promising way produce fuels and key chemical building blocks while reducing emissions. The reaction at atmospheric pressure mainly yields CH4 via methanation CO the reverse water-gas shift (RWGS) reaction. Describing catalyst features that control selectivity of these two pathways important determine formation specific products. At same time, identification morphological changes occurring catalysts under conditions can be crucial tune their...
The activity and selectivity of heterogeneous catalysts are strong functions the morphology catalytic active phase, which governs both density type sites. To realize materials with desired reactivity, cutting-edge often product novel synthetic strategies advanced computational studies. Combining these approaches allows for prediction fabrication motifs in a directed manner. However, catalyst phases ordinarily nanometer or atomic regime, small morphological changes can result large...
To limit further rising levels in methane emissions from stationary and mobile sources to enable promising technologies based on methane, the development of efficient combustion catalysts that completely oxidize CH4 CO2 H2O at low temperatures presence high steam concentrations is required. Palladium widely considered as one most materials for this reaction, a better understanding factors affecting its activity stability crucial design even more improved efficiently utilize precious metal....
Bimetallic catalytic materials are in widespread use for numerous reactions, as the properties of a monometallic catalyst often improved upon addition second metal. In studies with bimetallic catalysts, it remains challenging to establish clear structure–property relationships using traditional impregnation techniques, due presence multiple coexisting active phases different sizes, shapes, and compositions. this work, convenient approach prepare small uniform Pt/Pd nanocrystals tailorable...
Promoters enhance the performance of catalytic active phases by increasing rates, stability, and/or selectivity. The process identifying promoters is in most cases empirical and relies on testing a broad range catalysts prepared with random deposition promoter phases, typically no fine control over their localization. This issue particularly relevant supported bimetallic systems, where two metals are codeposited onto high-surface area materials. We here report use colloidal nanocrystals to...
Complete catalytic oxidation of methane in the presence steam at low temperatures (T < 400 °C) is a crucial reaction for emission control, yet it presents profound challenges. The activation strong C–H bond temperature difficult, and water present any realistic application poisons active surface promotes sintering Pd particles during reaction. Finding materials that can deliver high rates while being more resistant to imperative advancing several technological applications natural gas-based...
Although palladium-based materials are efficient catalysts for methane combustion, H2O-poisoning remains a significant problem at low operating temperatures (<450 °C). It is research challenge to find that can withstand water while delivering rates comparable the dry PdO phase. Therefore, an in situ sorption strategy could be advantageous maintaining high reaction. Here, we investigate sorbents used remove produced by reaction, which significantly enhances activity of Pd/CeO2 catalyst...
Low-temperature removal of noxious environmental emissions plays a critical role in minimizing the harmful effects hydrocarbon fuels. Emission-control catalysts typically consist large quantities rare, noble metals (e.g., platinum and palladium), which are expensive environmentally damaging to extract. Alloying with cheaper base offers potential boost catalytic activity while optimizing use metals. In this work, we show that PtxCu100-x prepared from colloidal nanocrystals more active than...
Platinum nanoparticles (NPs) supported by titania exhibit a strong metal-support interaction (SMSI)[1] that can induce overlayer formation and encapsulation of the NP's with thin layer support material. This modifies catalyst's properties, such as increasing its chemoselectivity[2] stabilizing it against sintering.[3] Encapsulation is typically induced during high-temperature reductive activation be reversed through oxidative treatments.[1] However, recent findings indicate stable in...
Machine learning research has long focused on models rather than datasets, and prominent datasets are used for common ML tasks without regard to the breadth, difficulty, faithfulness of underlying problems. Neglecting fundamental importance data given rise inaccuracy, bias, fragility in real-world applications, is hindered by saturation across existing dataset benchmarks. In response, we present DataPerf, a community-led benchmark suite evaluating data-centric algorithms. We aim foster...
The conversion of CO2 into fuels and chemicals is an attractive option for mitigating emissions. Controlling the selectivity this process beneficial to produce desirable liquid fuels, but C-C coupling a limiting step in reaction that requires high pressures. Here, we propose strategy favor on supported Ru/TiO2 catalyst by encapsulating it within polymer layers imine-based porous organic controls its selectivity. Such confinement modifies hydrogenation behavior Ru surface, significantly...
Noble metal-based catalysts are ubiquitous because of their high activity and stability. However, they irreversibly deteriorate over time especially in high-temperature applications. In these conditions, sintering is the main reason for deactivation, understanding how occurs gives opportunity to mitigate detrimental processes. Previous studies successfully distinguished between two fundamental modes, namely, particle migration coalescence (PMC) Ostwald ripening (OR). differentiation surface-...
Synthesis of monodisperse nanoparticles (NPs) with precisely controlled size is critical for understanding their size-dependent properties. Although significant synthetic developments have been achieved, it still challenging to synthesize well-defined NPs in a predictive way due lack in-depth mechanistic reaction kinetics. Here we use synchrotron-based small-angle X-ray scattering (SAXS) monitor situ the formation palladium (Pd) through thermal decomposition Pd–TOP (TOP: trioctylphosphine)...
It is well-known that water has a detrimental effect on the low-temperature methane combustion activity of palladium catalysts. However, when transient (i.e., light-off or ignition–extinction experiments) catalysts compared, effects adsorption–desorption phenomena are seldom directly considered. While these important to keep in mind studying support-dependent activity, they crucial selecting catalyst diluent. In many cases, properties "inert" reactor diluents may dominate Pd catalyst. this...
Supported metal nanoparticles are essential components of high-performing catalysts, and their structures intensely researched. In comparison, nanoparticle spatial distribution in powder catalysts is conventionally not quantified, the influence this collective property on catalyst performance remains poorly investigated. Here, we demonstrate a general colloidal self-assembly method to control uniformity common industrial supports. We quantify distributions nanoscale using image statistics...
Metal nanoparticles have superior properties for a variety of applications. In many cases, the improved performance metal is tightly correlated with their size and atomic composition. To date, colloidal synthesis most commonly used technique to produce nanoparticles. However, currently laboratory scale that has not been applied at larger scales. One greatest challenges facing large-scale large volume long-chain hydrocarbon solvents surfactants needed synthesis, which can dominate cost...
To overcome limitations of open surgery artificial intelligence (AI) models by curating the largest collection annotated videos and to leverage this AI-ready data set develop a generalizable multitask AI model capable real-time understanding clinically significant surgical behaviors in prospectively collected real-world videos.
Pd- and Pt-based catalysts are highly studied materials due to their widespread use in emissions control catalysis. However, claims continue vary regarding the active phase oxidation state of metals. Different conclusions have likely been reached heterogeneous nature such containing various metal nanoparticle sizes compositions, which may each possess unique redox features. In this work, using uniform nanocrystal catalysts, we study effect particle size alloying on properties Pd-based show...