A5065623016- Catalytic Processes in Materials Science
- Catalysis and Oxidation Reactions
- Zeolite Catalysis and Synthesis
- Electrocatalysts for Energy Conversion
- Metal-Organic Frameworks: Synthesis and Applications
- Nanomaterials for catalytic reactions
- Ammonia Synthesis and Nitrogen Reduction
- Mesoporous Materials and Catalysis
- Catalysis and Hydrodesulfurization Studies
- Advanced Photocatalysis Techniques
- Gas Sensing Nanomaterials and Sensors
- Advanced ceramic materials synthesis
- Asymmetric Hydrogenation and Catalysis
- Membrane Separation Technologies
- Seismic Waves and Analysis
- Catalysts for Methane Reforming
- Luminescence Properties of Advanced Materials
- Machine Learning in Materials Science
- Carbon dioxide utilization in catalysis
- Solid-state spectroscopy and crystallography
- X-ray Diffraction in Crystallography
- Methane Hydrates and Related Phenomena
- Industrial Gas Emission Control
- Graphene research and applications
- Nanocluster Synthesis and Applications
Pacific Northwest National Laboratory
2018-2024
Robert Bosch (Germany)
2024
Government of the United States of America
2022
University of South Carolina
2013-2021
Richland College
2019
Rensselaer Polytechnic Institute
2019
Institute for Fuels and Renewable Energy
2017
The majority of harmful atmospheric CO and NOx emissions are from vehicle exhausts. Although there has been success addressing at temperatures above 250 °C with selective catalytic reduction technology, during cold start (when the temperature is below 150 °C), a major challenge. Herein, we show can completely eliminate both simultaneously under realistic exhaust flow, using highly loaded (2 wt %) atomically dispersed palladium in extra-framework positions small-pore chabazite material as...
ADVERTISEMENT RETURN TO ISSUEPREVViewpointNEXTLow-Temperature Methane Oxidation for Efficient Emission Control in Natural Gas Vehicles: Pd and BeyondDong JiangDong JiangThe Gene Linda Voiland School of Chemical Engineering Bioengineering, Washington State University, Pullman, 99164, United StatesMore by Dong Jianghttp://orcid.org/0000-0003-0444-7865, Konstantin KhivantsevKonstantin KhivantsevInstitute Integrated Catalysis, Pacific Northwest National Laboratory, Richland, 99354,...
Abstract A single‐atom Pt 1 /CeO 2 catalyst formed by atom trapping (AT, 800 °C in air) shows excellent thermal stability but is inactive for CO oxidation at low temperatures owing to over‐stabilization of 2+ a highly symmetric square‐planar O 4 coordination environment. Reductive activation form nanoparticles (NPs) results enhanced activity; however, the NPs are easily oxidized, leading drastic activity loss. Herein we show that tailoring local environment isolated thermal‐shock (TS)...
Nondegradable polyolefin plastics pose severe environmental threats and thus demand efficient upcycling technologies. In this work, we discovered that low-loading (≤0.25 wt %) Ru/CeO2 exhibits remarkable catalytic performance in the hydrogenolysis of polypropylene (PP), polyethylene (PE), n-C16H34 is superior to high-loading (≥0.5 Ru/CeO2. They possess high PP conversion efficiency (sevenfold increase over current literature reports), low selectivity toward undesired CH4, good isomerization...
Atom trapping leads to catalysts with atomically dispersed Ru1O5 sites on (100) facets of ceria, as identified by spectroscopy and DFT calculations. This is a new class ceria-based materials Ru properties drastically different from the known M/ceria materials. They show excellent activity in catalytic NO oxidation, critical step that requires use large loadings expensive noble metals diesel aftertreatment systems. Ru1/CeO2 stable during continuous cycling, ramping, cooling well presence...
Model Pd/SSZ-13 with high dispersion of Pd ions (0.1 and 1 wt % Pd) was synthesized. The material characterized Fourier transform infrared (FTIR) cryo-scanning transmission electron microscopy. Adsorption NO leads to the formation Pd(II)–NO Pd(I)–NO complexes as well NO+ species that replace residual H+ (extra-framework) sites. These nitrosyl have notable thermal stability, resistance decomposition under vacuum at 200 °C. Addition molecular oxygen NO-containing stream improves NOx storage...
We demonstrated for the first time that inkjet printing can be a low-cost, easy, fast, and scalable method depositing ultrathin (7.5–60 nm) uniform graphene oxide (GO) nanofiltration membranes on polymeric supports highly effective water purification.
We provide the first observation and characterization of super electrophilic metal cations on a solid support. For Pd/SSZ-13, results our combined experimental (Fourier transform infrared spectroscopy, X-ray photoelectron high-angle annular dark-field scanning transmission electron microscopy) density functional theory study reveal that Pd ions in zeolites, previously identified as Pd+3 Pd+4, are, fact, present Pd+2 species (charge-transfer complex/ion pair with negatively charged framework...
Abstract We show for the first time that atomically dispersed Rh cations on ceria, prepared by a high‐temperature atom‐trapping synthesis, are active species (CO+NO) reaction. This provides direct link with organometallic homogeneous I complexes capable of catalyzing dry The thermally stable in 0.1 wt % 1 /CeO 2 achieve full NO conversion turn‐over‐frequency (TOF) around 330 h −1 per atom at 120 °C. Under conditions, main product above 100 °C is N O being minor product. presence water...
Abstract The analogy between single‐atom catalysts (SACs) and molecular predicts that the specific catalytic activity of these systems is constant. We provide evidence this prediction not necessarily true. As a case in point, we show over ceria‐supported single Pd atoms linearly increases with metal atom density, originating from cumulative enhancement CeO 2 reducibility. long‐range electrostatic footprints (≈1.5 nm) around each site overlap other as surface density increases, resulting an...
Pd-ion-exchanged zeolites have emerged as promising materials for the adsorption and oxidation of air pollutants. For low-temperature vehicle exhaust, dispersed Pd ions can adsorb NOx even in H2O-rich exhaust containing carbon monoxide. To understand this phenomenon, changes ligand environment to be monitored situ. Herein, we directly observe activation hydrated ion shielded by H2O into a carbonyl–nitrosyl complex Pd2+(NO)(CO) SSZ-13 zeolite. The subsequent thermal desorption ligands on...
We report the use of MIL-120 as a water-stable and cost-effective metal-organic framework (MOF) for selectively capturing CO2 from wet flue gas. Synthesized using inexpensive environmentally benign reagents in water, possesses one-dimensional pores decorated with hydroxyl-bridged Al(III) ions benzene rings an interstitial spacing 4.78 Å. Carbon dioxide isotherms show steep uptake at low pressure, affinity is 44 kJ mol−1. CO2-loading 13C solid-state nuclear magnetic resonance Fourier...
Ultrasmall Pd4 clusters form in the micropores of FER zeolite during low-temperature treatment (100 °C) presence humid CO gas. They effectively catalyze oxidation below 100 °C, whereas Pd nanoparticles are not active as they poisoned by CO. Using catalytic measurements, infrared (IR) spectroscopy, X-ray absorption spectroscopy (EXAFS), microscopy, and density functional theory calculations, we provide molecular-level insight into this previously unreported phenomenon. get covered with at low...
Abstract γ‐alumina is one of the oldest and most important commercial catalytic materials with high surface area stability. These attributes enabled its use as first large‐scale heterogeneous catalyst for ethanol dehydration. Despite progress in characterization nature specific sites on that are responsible unique properties has remained obscure controversial. By using combined infrared spectroscopy, electron microscopy solid‐state nuclear magnetic resonance measurements we identify...
Pd-loaded FER and SSZ-13 zeolites as low-temperature passive NOx adsorbers (PNA) are compared under practical conditions. Vehicle cold start exposes the material to CO a range of concentrations, necessitating systematic exploration effect on performance isolated Pd ions in PNA. The NO release temperature both decreases gradually with an increase concentration from few hundred thousand ppm. This beneficial results local nano-"hot spot" formation during oxidation. Dissimilar Pd/SSZ-13,...
Steamed zeolites exhibit improved catalytic properties for hydrocarbon activation (alkane cracking and dehydrogenation). The nature of this practically important phenomenon has remained a mystery the last six decades was suggested to be related increased strength zeolitic Bronsted acid sites after dealumination. We now utilize state-of-the-art infrared spectroscopy measurements prove that during steaming, aluminum oxide clusters evolve (due hydrolysis Al out framework positions with...
Rh(CO)2 complexes anchored on various dealuminated HY zeolites were used as precursors for the surface-mediated synthesis of Rh(CO)(H)x species. The carbonyl ligands initial react with gas-phase C2H4 to form Rh(CO)(C2H4) species and subsequently well-defined when former are exposed H2 at room temperature. Zeolite-supported Rh(C2H4)2 Rh(NO)2 can also be precursors, but both must converted into first allow formation thus formed characterized by a set νCO νRhH bands in their Fourier transfrom...
Abstract The majority of harmful atmospheric CO and NO x emissions are from vehicle exhausts. Although there has been success addressing at temperatures above 250 °C with selective catalytic reduction technology, during cold start (when the temperature is below 150 °C), a major challenge. Herein, we show can completely eliminate both simultaneously under realistic exhaust flow, using highly loaded (2 wt %) atomically dispersed palladium in extra‐framework positions small‐pore chabazite...
Pd-based catalysts are widely used in the oxidation of CH4 and have a significant impact on global warming. However, understanding their active sites remains controversial, because interconversion between Pd PdO occurs consecutively during reaction. Understanding intrinsic under reaction conditions is critical for developing highly selective catalysts. In this study, we demonstrated that partially oxidized palladium (PdOx) surface plays an important role oxidation. Regardless whether initial...