While calibrating a new scientific apparatus at the ALS, researchers discovered that ultraviolet light can break up sulfur dioxide (SO2) in a new way, with molecular oxygen (O2) as an unexpected product. The discovery sheds light on Earth’s Great Oxygenation Event 2.4 billion years ago, when atmospheric oxygen levels first began to rise. Read more »
Nicotine Protonation in Simulated Vaping Aerosols
To better understand how e-cigarette additives alter nicotine chemistry and users’ perceptions of vaping, researchers used x-ray spectroscopy technology at the Advanced Light Source to analyze the acid-base equilibria of additive-enhanced nicotine in simulated vaping aerosols. Read more »
The Identity and Chemistry of C7H7 Radicals Observed during Soot Formation
Recent work suggests that resonance-stabilized radicals may participate in chain reactions that lead to soot-particle formation, but their identities and chemistry are poorly understood. C7H7 is often observed in aerosol mass spectra and is generally assumed to be benzyl, the most thermodynamically stable C7H7 isomer. It has now been shown that the identities of these isomers are far more varied, and their chemistry is far more complex, than previously appreciated. Read more »
SO2 Photodissociation at 193 nm Directly Forms S(3P) + O2(3Σg–): Implications for the Archean Atmosphere on Earth
Sulfur isotope patterns in ancient rock layers inform our understanding of Earth’s Archean atmosphere. Before the Great Oxygenation Event (~2.4 billion years ago), hard ultraviolet light penetrated into the Earth’s surface, photodissociating sulfur dioxide directly to S + O2. This new product channel may help resolve discrepancies in the Earth’s evolutionary history. Read more »
Extreme Closeup of Copper Electrocatalysts in Action
Researchers at Berkeley Lab have made real-time movies of copper nanoparticles as they evolve to convert carbon dioxide and water into renewable fuels and chemicals. Their new insights could help advance the next generation of solar fuels. Read more »
How a Record-Breaking Copper Catalyst Converts CO2 Into Liquid Fuels
Scientists know that copper has a special ability to transform CO2 into valuable chemicals and fuels. But for many years, they struggled to understand how. Now, a research team has gained new insight by capturing real-time movies of copper nanoparticles as they convert CO2 and water into renewable fuels and chemicals: ethylene, ethanol, and propanol, among others. Read more »
First Direct Measurement of Elusive Donnan Potential
Researchers performed the first direct measurement of the Donnan electrical potential, which arises from an imbalance of charges at membrane-solution interfaces. Considered unmeasurable for over a century, the Donnan potential is relevant to a wide range of fields, from cell biology to energy storage and water desalination. Read more »
The Donnan Potential, Revealed at Last
Researchers at the ALS recently led the first direct measurement of the Donnan potential, an electric potential that arises from an imbalance of charges at the interface of a charged membrane and a liquid. The work could yield new insights in areas such as ion transport through cellular membranes, ion exchange membranes in energy storage strategies, and water purification technologies. Read more »
Gas-phase synthesis of racemic helicenes and their potential role in the enantiomeric enrichment of sugars and amino acids in meteorites
Molecular-beam experiments with isomer-selective photoionization via a targeted, vinylacetylene-mediated gas-phase reaction of aromatic helicenyl radicals coupled with electronic structure calculations and astrochemical modeling reveal an elegant synthetic route to racemic helicenes – ortho-fused polycyclic aromatic hydrocarbons (PAHs), in which benzene building blocks form helically-shaped molecules. Read more »
Watching Nanoparticle Chemistry and Structure Evolve
Using a multimodal approach, researchers learned how chemical properties correlate with structural changes during nanoparticle growth. The work will enable a greater understanding of the mechanisms affecting the durability of nanoparticles used to catalyze a broad range of chemical reactions, including clean-energy reactions. Read more »
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