Adsorption of carbon monoxide on a nanosized apex facet of a [111]-oriented Pt field emitter tip was studied under high electrostatic field conditions (15-20V/nm) by field ion appearance energy spectroscopy (FIAES). Weakly bound highly mobile CO species have been detected and their possible role in surface reactions such as CO oxidation on Pt was elucidated. The FIAES results are compared with those of vibrational sum frequency generation (SFG) spectroscopy of CO adsorption on a macroscopic Pt(111) single crystal, in a gas pressure range from UHV to atmospheric. SFG and FIAES are complementary in that SFG mainly provides information on strongly bound CO molecules, whereas FIAES nearly exclusively detects weakly bound species. Both high-field and high-pressure studies indicate the presence of a compressed CO adlayer including weakly bound species. The high-field mimics the high gas pressure, leading to similar high adsorbate coverage, which is required for the formation of weakly bound highly mobile CO species, which may be the active entities in CO oxidation.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.ultramic.2008.09.011 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The folded auto-inhibited state of kinesin-1 is stabilized by multiple weak interactions and binds weakly to microtubules. Here we investigate the extent to which homodimeric kinesin-1 lacking light chains is activated by the dynein activating adaptor BicD. We show that one or two kinesins can bind to the central region of BicD (CC2), a region distinct from that which binds dynein-dynactin (CC1) and cargo-adaptor proteins (CC3).
View Article and Find Full Text PDFSteering the Absorption Configuration of Intermediates over Pd-Based Electrocatalysts toward Efficient and Stable CO Reduction.
J Am Chem Soc
January 2025
Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Kowloon 999077, Hong Kong, China.
Palladium (Pd) catalysts are promising for electrochemical reduction of CO to CO but often can be deactivated by poisoning owing to the strong affinity of *CO on Pd sites. Theoretical investigations reveal that different configurations of *CO endow specific adsorption energies, thereby dictating the final performances. Here, a regulatory strategy toward *CO absorption configurations is proposed to alleviate CO poisoning by simultaneously incorporating Cu and Zn atoms into ultrathin Pd nanosheets (NSs).
View Article and Find Full Text PDFHow to Efficiently Annotate Images for Best-Performing Deep Learning-Based Segmentation Models: An Empirical Study with Weak and Noisy Annotations and Segment Anything Model.
J Imaging Inform Med
January 2025
Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA.
Deep neural networks (DNNs) have demonstrated exceptional performance across various image segmentation tasks. However, the process of preparing datasets for training segmentation DNNs is both labor-intensive and costly, as it typically requires pixel-level annotations for each object of interest. To mitigate this challenge, alternative approaches such as using weak labels (e.
View Article and Find Full Text PDFTransient Allosteric Regulation of Catalysis by Effector Switching in a Pt2L4 Cage.
Angew Chem Int Ed Engl
January 2025
University of Amsterdam Van 't Hoff Institute for Molecular Sciences: Universiteit van Amsterdam Van 't Hoff Institute for Molecular Sciences, HIMS, NETHERLANDS, KINGDOM OF THE.
The complexity of allosteric enzymatic regulation continues to inspire synthetic chemists seeking to emulate interconnected biological systems. In this work, a Pt2L4 cage capable of catalyzing the cyclization reaction of an alkynoic tosyl amide is orthogonally coupled to a diacid-catalyzed carbodiimide-hydration cycle. This new Pt-catalyzed cyclization reaction is demonstrated to exhibit electronic regulation by inclusion of different guest effectors.
View Article and Find Full Text PDFDevelopment of an G Protein-Coupled Receptor Fragment Molecule Screening Approach with High-Resolution Magic Angle Spinning Nuclear Magnetic Resonance.
ACS Chem Biol
January 2025
Department of Chemistry, University of Florida, Gainesville Florida 32611, United States.
Small molecules are essential for investigating the pharmacology of membrane proteins and remain the most common approach for therapeutically targeting them. However, most experimental small molecule screening methods require ligands containing radiolabels or fluorescent labels and often involve isolating proteins from their cellular environment. Additionally, most conventional screening methods are suited for identifying compounds with moderate to higher affinities ( < 1 μM) and are less effective at detecting lower affinity compounds, such as weakly binding molecular fragments.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!