AI Article Synopsis
Article Abstract
Distinct from inert bulk gold, nanoparticulate gold has been found to possess remarkable catalytic activity towards oxidation reactions. The catalytic performance of nanoparticulate gold strongly depends on size and support, and catalytic activity usually cannot be observed at characteristic sizes larger than 5 nm. Interestingly, significant catalytic activity can be retained in dealloyed nanoporous gold (NPG) even when its feature lengths are larger than 30 nm. Here we report atomic insights of the NPG catalysis, characterized by spherical-aberration-corrected transmission electron microscopy (TEM) and environmental TEM. A high density of atomic steps and kinks is observed on the curved surfaces of NPG, comparable to 3-5 nm nanoparticles, which are stabilized by hyperboloid-like gold ligaments. In situ TEM observations provide compelling evidence that the surface defects are active sites for the catalytic oxidation of CO and residual Ag stabilizes the atomic steps by suppressing {111} faceting kinetics.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1038/nmat3391 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Consecutive C-C Coupling of CH and CO Mediated by Heteronuclear Metal Cations CuTa.
J Am Chem Soc
December 2024
Henan Key Laboratory of Crystalline Molecular Functional Materials, College of Chemistry, Zhengzhou University, Zhengzhou 450001, China.
The conversion of methane and carbon dioxide to form C products is of great interest but presents a long-standing grand challenge due to the significant obstacle of activating the inert C-H and C═O bonds as well as forming the C-C bonds. Herein, the consecutive C-C coupling of CH and CO was realized by using heteronuclear metal cations CuTa, and the desorption of HC═C═O molecules was evidenced by state-of-the-art mass spectrometry. The CuTa reaction system is significantly different from the homonuclear metal systems of Cu and Ta.
View Article and Find Full Text PDFPlatinum nanoparticles wrapped in carbon-dot-films as oxygen reduction reaction catalysts prepared by solution plasma sputtering.
Nanoscale Adv
December 2024
Department of Chemical Systems Engineering, Graduate School of Engineering, Nagoya University Furo-cho, Chikusa-ku Nagoya 464-8603 Japan
Fuel cells have become increasingly important in recent years because of their high energy efficiency and low environmental impact. However, key challenges remain in the widespread adoption of fuel-cell vehicles, including reducing Pt usage in catalysts and improving their durability. In this study, a high-performance Pt@carbon-dot-film core-shell catalyst was successfully synthesized using a nonequilibrium reaction field, , solution plasma (SP) process, by adjusting the electrolyte pH.
View Article and Find Full Text PDFA new mesoporous Ce-Mn-LDH-based Co-MOF nano-composite for the green synthesis of tetrazoloquinazolines.
Nanoscale Adv
November 2024
Department of Organic Chemistry, Faculty of Chemistry and Petroleum Sciences, Bu-Ali Sina University Hamedan Iran +98-81-31408025 +98-81-38380922.
Tannic acid (TA), as a plant polyphenol, has many active sites for chelation with metals, so TA-oligomers (TA-Olig) were used for the first time as ligands on the surface of Ce-Mn-LDH to prepare the layered double hydroxide-based metal-organic framework (Ce-Mn-LDH@CPTMS@TA-Olig@Co-MOF = E) nanocomposite. In this regard, a homogeneous water/ethanol solution was prepared by sol-gel method using polyethylene glycol and ammonia solution, and then TA was converted into a set of oligomers in the presence of formaldehyde. In the next step, Ce-Mn-LDH was prepared in a ratio of 1 : 4 of Ce to Mn, modified with 3-chloropropylmethoxysilane, functionalized by TA-Olig, and then cobalt salt was used to prepare E.
View Article and Find Full Text PDFCharacterization of VldE (Spr1875), a Pneumococcal Two-State l,d-Endopeptidase with a Four-Zinc Cluster in the Active Site.
ACS Catal
December 2024
Department of Crystallography and Structural Biology, Consejo Superior de Investigaciones Científicas, Instituto de Química-Física "Blas Cabrera", Madrid 28006, Spain.
Remodeling of the pneumococcal cell wall, carried out by peptidoglycan (PG) hydrolases, is imperative for maintaining bacterial cell shape and ensuring survival, particularly during cell division or stress response. The protein Spr1875 plays a role in stress response, both regulated by the VicRK two-component system (analogous to the WalRK TCS found in Firmicutes). Modular Spr1875 presents a putative cell-wall binding module at the N-terminus and a catalytic C-terminal module (Spr1875) connected by a long linker.
View Article and Find Full Text PDFBoron Designer Enzyme with a Hybrid Catalytic Dyad.
ACS Catal
December 2024
Stratingh Institute for Chemistry, University of Groningen, Groningen 9747 AG, The Netherlands.
Genetically encoded noncanonical amino acids can introduce new-to-nature activation modes into enzymes. While these amino acids can act as catalysts on their own due to their inherent chemical properties, interactions with adjacent residues in an enzyme, such as those present in natural catalytic dyads or triads, unlock a higher potential for designer enzymes. We incorporated a boron-containing amino acid into the protein scaffold RamR to create an active enzyme for the kinetic resolution of α-hydroxythioesters.
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!