A5074681682- Spectroscopy and Quantum Chemical Studies
- Zeolite Catalysis and Synthesis
- Catalysis and Hydrodesulfurization Studies
- Spectroscopy and Laser Applications
- Photochemistry and Electron Transfer Studies
- Chemical Synthesis and Characterization
- Catalysis for Biomass Conversion
- Advanced NMR Techniques and Applications
- Analytical Chemistry and Sensors
- Laser-Matter Interactions and Applications
- Metal-Organic Frameworks: Synthesis and Applications
- Catalytic Processes in Materials Science
- Solid-state spectroscopy and crystallography
- Mass Spectrometry Techniques and Applications
- Catalysis and Oxidation Reactions
- Quantum, superfluid, helium dynamics
- Spectroscopy Techniques in Biomedical and Chemical Research
- Advanced Chemical Physics Studies
- Electrochemical Analysis and Applications
- Asymmetric Hydrogenation and Catalysis
University of Chicago
2020-2024
Chicago Institute for Psychoanalysis
2020-2024
Argonne National Laboratory
2021
University of Virginia
2015-2016
Brookhaven National Laboratory
2016
Rhenium substantially promotes the rate of Pt-catalyzed glycerol hydrogenolysis to propanediols and shifts product selectivity from 1,2-propanediol a mixture 1,2 1,3-propanediols. This work presents experimental evidence for tandem dehydration–hydrogenation mechanism that occurs over bifunctional Pt–Re catalyst. Infrared spectroscopy adsorbed pyridine aqueous-phase hydrolysis propyl acetate were used identify quantify Brønsted acid sites associated with Re component. Near-ambient-pressure...
A molecular description of the structure and behavior water confined in aluminosilicate zeolite pores is a crucial component for understanding acid chemistry under hydrous conditions. In this study, we use combination ultrafast two-dimensional infrared (2D IR) spectroscopy ab initio dynamics (AIMD) to study H2O highly hydrated HZSM-5 (∼13 ∼6 equivalents per Al atom). The 2D IR spectrum reveals correlations between vibrations both terminal H-bonded O–H groups continuum absorption excess...
The protonation behavior of zeolite Brønsted acid sites (BAS) in the presence water is important for performance these widely used catalysts. Despite extensive study, number molecules necessary deprotonation not well understood, large part because experiments have been unable to access this information. In work, we report experimental evidence full BAS two or more molecules, with a energy 1.6 kcal/mol. Linear IR absorption and 2D spectra were measured over wide range controlled hydration...
The aqueous proton is a common and long-studied species in chemistry, yet there currently intense interest devoted to understanding its hydration structure transport dynamics. Typically described terms of two limiting structures observed gas-phase clusters, the Zundel H5O2+ Eigen H9O4+ ions, less clear due heterogeneity hydrogen bonding environments room-temperature structural fluctuations water. linear infrared (IR) spectrum, which reports on configurations, challenging interpret because it...
Ion pairing is a fundamental consideration in many areas of chemistry and has implications wide range sciences technologies that include batteries organic photovoltaics. Ions solution are known to inhabit multiple possible states, including free ions (FI), contact ion pairs (CIP), solvent-separated (SSIP). However, solutions radicals nonmetal electrolytes, it often difficult distinguish between these states. In the first part this work, we report evidence for formation SSIPs low-polarity...
In acidic HZSM-5 zeolite, the reactivity of a methanol molecule interacting with zeolite proton is amenable to modification via coadsorbing stochiometric amount an electron density donor E form [(E)(CH3OH)(HZ)] complex. The rate in this complex undergoing dehydration dimethyl ether was determined for series affinity (PA) ranging from 659 kJ mol–1 C6F6 825 C4H8O and found follow expression: Ln(Rate) – Ln(RateN2) = β(PA PAN2)γ, where N2 reference β γ are constants. This trend probably due...
Abstract The hydrogenation rates of C=C and C=O bonds in methyl vinyl ketone crotonaldehyde were measured over a series silica‐supported Pt‐Re catalysts (1:1 atomic ratio Pt/Re) liquid water with H 2 (15 psig) at 333 K. did not produce any unsaturated alcohol because the rapid relative to that C=O. addition Re Pt impacted rate negatively crotonaldehyde, but promoted selectivity which increased from 5 % on 21 Pt‐Re. also 2‐butanone, whereas little effect was observed during butanal. results...
Hydrogen bonding between water molecules and zeolite Bro̷nsted acid sites (BAS) has received much attention due to the significant influence of on adsorption catalytic properties these widely used porous materials. When a single molecule is adsorbed at BAS, O-H stretch vibration decreases in frequency splits into two extraordinarily broad bands peaked near 2500 2900 cm-1 infrared (IR) spectrum. This doublet feature predominant IR signature identify interpret water-BAS H-bonding low hydration...
We report the generation and characterization of microjoule level, broad bandwidth femtosecond pulses in mid-infrared (MIR) using optical parametric amplification continuum MIR seed GaSe. The signal (3 μm) idler (6 have energies 6 μJ 3 with bandwidths ∼950 cm-1 650 FWHM pulse lengths 34 fs 80 fs. Broadband 2D IR spectra O-H N-H transitions are acquired beam demonstrating capabilities this source for cross peak line shape measurements.
In recent years, new methods of generating continuum mid-infrared pulses through filamentation in gases have been developed for ultrafast time-resolved infrared vibrational spectroscopy. The generated can thousands wavenumbers bandwidth, spanning the entire mid-IR region while retaining pulse length below 100 fs. This technology has had a significant impact on problems involving structural dynamics congested spectra with broad features, such as those found aqueous solutions and molecules...