A5013342376- Catalytic Processes in Materials Science
- Catalysis and Oxidation Reactions
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Machine Learning in Materials Science
- Electrocatalysts for Energy Conversion
- Fuel Cells and Related Materials
- Advanced Mathematical Modeling in Engineering
- Silicon Carbide Semiconductor Technologies
- Advanced battery technologies research
- Metal-Organic Frameworks: Synthesis and Applications
- Semiconductor materials and devices
- Advanced ceramic materials synthesis
- Surface Chemistry and Catalysis
- Boron and Carbon Nanomaterials Research
- Covalent Organic Framework Applications
- Advancements in Battery Materials
- Catalysis and Hydrodesulfurization Studies
- Semiconductor materials and interfaces
- Catalysts for Methane Reforming
- Ammonia Synthesis and Nitrogen Reduction
- Nanomaterials for catalytic reactions
- Carbon dioxide utilization in catalysis
- CO2 Reduction Techniques and Catalysts
- Luminescence and Fluorescent Materials
University of South Carolina
2016-2023
Harvard University
2016-2019
Harvard University Press
2019
Columbia College - South Carolina
2018
University of California, Riverside
2013-2017
Oregon State University
2017
FORTH Institute of Chemical Engineering Sciences
2008-2017
Robert Bosch (Germany)
2016
University of Patras
2006-2012
Foundation for Research and Technology Hellas
2006-2011
It remains a grand challenge to replace platinum group metal (PGM) catalysts with earth-abundant materials for the oxygen reduction reaction (ORR) in acidic media, which is crucial large-scale deployment of proton exchange membrane fuel cells (PEMFCs). Here, we report high-performance atomic Fe catalyst derived from chemically Fe-doped zeolitic imidazolate frameworks (ZIFs) by directly bonding ions ligands within 3D frameworks. Although ZIF was identified as promising precursor, new...
Platinum group metal (PGM)-free catalysts for oxygen reduction reaction are essential affordable fuel cells.
Abstract FeN 4 moieties embedded in partially graphitized carbon are the most efficient platinum group metal free active sites for oxygen reduction reaction acidic proton‐exchange membrane fuel cells. However, their formation mechanisms have remained elusive decades because Fe−N bond process always convolutes with uncontrolled carbonization and nitrogen doping during high‐temperature treatment. Here, we elucidate site through hosting Fe ions into a nitrogen‐doped followed by controlled...
Highly ordered Pt alloy structures are proven effective to improve their catalytic activity and stability for the oxygen reduction reaction (ORR) proton exchange membrane fuel cells. Here, we report a new approach preparing Pt3Co intermetallic nanoparticles through facile thermal treatment of supported on Co-doped metal-organic-framework (MOF)-derived carbon. In particular, atomically dispersed Co sites, which originally embedded into MOF-derived carbon, diffuse nanocrystals form structures....
Increasing catalytic activity and durability of atomically dispersed metal-nitrogen-carbon (M-N-C) catalysts for the oxygen reduction reaction (ORR) cathode in proton-exchange-membrane fuel cells remains a grand challenge. Here, high-power durable Co-N-C nanofiber catalyst synthesized through electrospinning cobalt-doped zeolitic imidazolate frameworks into selected polyacrylonitrile poly(vinylpyrrolidone) polymers is reported. The distinct porous fibrous morphology hierarchical structures...
A carbon support with favorable balance between graphitization and hierarchical porosity is promising to address corrosion issue in cathode catalysts for proton exchange membrane fuel cells (PEMFCs).
Integrating the atomically dispersed and nitrogen coordinated single Fe site-rich carbon support ordered PtCo intermetallic nanoparticles is an effective approach to designing high-performance low-PGM fuel cell catalysts for transportation.
Spinel NiCo2O4 is considered a promising precious metal-free catalyst that also carbon-free for oxygen electrocatalysis. Current efforts mainly focus on optimal chemical doping and substituent to tune its electronic structures enhanced activity. Here, we study morphology control elucidate the morphology-dependent performance bifunctional reduction reaction (ORR) evolution (OER). Three types of catalysts with significantly distinct morphologies were prepared using temple-free, Pluronic-123...
Abstract Ammonia (NH 3 ) electrosynthesis gains significant attention as NH is essentially important for fertilizer production and fuel utilization. However, electrochemical nitrogen reduction reaction (NRR) remains a great challenge because of low activity poor selectivity. Herein, new class atomically dispersed Ni site electrocatalyst reported, which exhibits the optimal yield 115 µg cm −2 h −1 at –0.8 V versus reversible hydrogen electrode (RHE) under neutral conditions. High faradic...
Single metal site Ni–N–C catalysts were designed concerning the particle size, content, and coordination structure for efficient CO 2 reduction.
Carbon supported and nitrogen coordinated single Mn site (Mn–N–C) catalysts are the most desirable platinum group metal (PGM)-free cathode for proton-exchange membrane fuel cells (PEMFCs) due to their insignificant Fenton reactions (vs. Fe), earth abundances Co), encouraging activity stability. However, current Mn–N–C suffer from high overpotential low intrinsic less dense MnN4 sites. Herein, we present a sulfur-doped catalyst (Mn–N–C–S) synthesized through an effective adsorption-pyrolysis...
Abstract Atomically dispersed FeN 4 active sites have exhibited exceptional catalytic activity and selectivity for the electrochemical CO 2 reduction reaction (CO2RR) to CO. However, understanding behind intrinsic morphological factors contributing properties of is still lacking. By using a Fe‐N‐C model catalyst derived from ZIF‐8, we deconvoluted three key structural elements sites, including particle sizes catalysts, Fe content, Fe−N bond structures. Their respective impacts on CO2RR were...
Abstract We elucidate the structural evolution of CoN 4 sites during thermal activation by developing a zeolitic imidazolate framework (ZIF)‐8‐derived carbon host as an ideal model for Co 2+ ion adsorption. Subsequent in situ X‐ray absorption spectroscopy analysis can dynamically track conversion from inactive Co−OH and Co−O species into active sites. The critical transition occurs at 700 °C becomes optimal 900 °C, generating highest intrinsic activity four‐electron selectivity oxygen...
Low-temperature direct ammonia fuel cells (DAFCs) can use carbon-neutral as a fuel, which has attracted increasing attention recently due to ammonia's low source-to-tank energy cost, easy transport and storage, wide availability.
Ammonia (NH3) has proved to be an effective alternative hydrogen in low-temperature fuel cells via its direct ammonia oxidation reaction (AOR). However, the kinetically sluggish AOR prohibitively hindered attractive cell (DAFC) applications. Here, we report efficient catalyst, which ternary PtIrNi alloy nanoparticles well dispersed on a binary composite support consisting of porous silicon dioxide (SiO2) and carboxyl-functionalized carbon nanotube (PtIrNi/SiO2-CNT-COOH) through...
Development of platinum group metal (PGM)-free and iron-free catalysts for the kinetically sluggish oxygen reduction reaction (ORR) is crucial proton-exchange membrane fuel cells. A major challenge their insufficient performance durability in electrode assembly (MEA) under practical hydrogen-air conditions. Herein, we report an effective strategy to synthesize atomically dispersed Mn–N–C from environmentally benign aqueous solution, instead traditional organic solvents. This innovative...
Carbon-supported nitrogen-coordinated single-metal site catalysts (i.e., M-N-C, M: Fe, Co, or Ni) are active for the electrochemical CO2 reduction reaction (CO2 RR) to CO. Further improving their intrinsic activity and selectivity by tuning N-M bond structures coordination is limited. Herein, we expand environments of M-N-C designing dual-metal sites. The Ni-Fe catalyst exhibited most efficient CO2RR promising stability compared other combinations. Advanced structural characterization...
Ammonia, as a promising hydrogen carrier, can be decomposed on Ru-free catalyst at economically feasible temperatures for on-site carbon-free generation.
The intrinsic instability of carbon largely limits its use for the oxygen reduction reaction (ORR) and evolution (OER) as a bifunctional catalyst in reversible fuel cells or water electrolyzers. Herein, we discovered that Mn doping has promotional role stabilizing nanocarbon catalysts ORR/OER alkaline media. Stable composites are derived from an inexpensive carbon/nitrogen precursor (i.e., dicyandiamide) quaternary FeCoNiMn alloy via template-free carbonization process. In addition to metal...
A one-pot synthesis is described to construct a composite of the amino-derivative Zr carboxylate metal–organic framework and silica gel (UiO-66-NH<sub>2</sub>@silica) as an efficient solid sorbent for hexavalent chromium.