Highly active and selective aerobic oxidation of KA-oil to cyclohexanone (precursor for adipic acid and ɛ-caprolactam) has been achieved in high yields using continuous-flow chemistry by utilizing uncapped noble-metal (Au, Pt & Pd) nanoparticle catalysts. These are prepared using a one-step in situ methodology, within three-dimensional porous molecular architectures, to afford robust heterogeneous catalysts. Detailed spectroscopic characterization of the nature of the active sites at the molecular level, coupled with aberration-corrected scanning transmission electron microscopy, reveals that the synthetic methodology and associated activation procedures play a vital role in regulating the morphology, shape and size of the metal nanoparticles. These active centers have a profound influence on the activation of molecular oxygen for selective catalytic oxidations.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/cssc.201501264 | DOI Listing |
Adv Sci (Weinh)
December 2024
Laboratory for Chemistry and Life Sciences, Tokyo Institute of Technology, Yokohama, Kanagawa, 226-8501, Japan.
Nanostructured Pt-based catalysts have attracted considerable attention for fuel-cell applications. This study introduces a novel one-pot and low-temperature polyol approach for synthesizing support-free, connected nanoparticles with non-Pt metal cores and Pt shells. Unlike conventional heat treatment methods, the developed support-free and Fe-free connected Pd@Pt (Pd@Pt) nanoparticle catalyst possesses a stable nanonetwork structure with a high surface area.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
School of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou 730050, PR China; Key Laboratory of Low Carbon Energy and Chemical Engineering of Gansu Province, Lanzhou 730050, PR China.
Heteroatom-doped carbon materials are widely used to improve the electrocatalytic oxidation of methanol; however, the underlying mechanisms driving this enhancement remain poorly understood. A major challenge lies in developing non-doped carbon supports with tunable intrinsic defect types tailored for metal-based catalysts. In this study, we synthesize a series of ordered mesoporous carbon (OMC) supports with adjustable edge defect densities by varying roasting temperatures and employing a zinc (Zn) evaporation strategy to systematically investigate the impact of edge defects on methanol oxidation reaction (MOR) performance.
View Article and Find Full Text PDFLangmuir
December 2024
Department of Chemistry and Materials Engineering, Faculty of Chemistry, Materials and Bioengineering, Kansai University, Suita, Osaka 564-8680, Japan.
In recent years, the advancement of high-frequency communication systems, particularly 5G and future 6G technologies, has increased the need for substrates that minimize signal loss and electromagnetic interference. Glass substrates are highly desirable for these applications due to their low dielectric constant and excellent surface smoothness. However, conventional electroless Cu plating methods struggle to achieve strong adhesion between Cu and the smooth, low-polarity surface of glass, making this an important challenge to address.
View Article and Find Full Text PDFACS Appl Mater Interfaces
December 2024
Department of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States.
Artificial N fixation via the electrocatalytic nitrogen (N) reduction reaction (NRR) has been recently promoted as a rational route toward reducing energy consumption and CO emission as compared with the traditional Haber-Bosch process. Nevertheless, optimizing NRR relies on developing highly efficient electrocatalysts. Herein, we report on the reliable and reproducible synthesis of two promising electrocatalysts in either the presence or absence of Ketjenblack (KB), namely, ZrO-ZrN@KB and ZrO-ZrN systems, synthesized through the nitriding of Zr.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602, Japan.
PtGd alloy nanoparticles supported in hollow mesoporous carbon spheres (HMCS; ) were successfully prepared by the thermal reduction of organometallic Pt and Gd complexes without oxygen atoms supported in the pores of HMCS. The structures of PtGd alloy nanoparticles were fully characterized by TEM, HAADF-STEM-EDS, XRD, XAFS, and XPS, suggesting the formation of uniform PtGd alloy nanoparticles with an average particle size of 5.9 nm.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!