Metal catalysts (e.g., Pt) have a variety of applications in energy conversion devices including polymer electrolyte fuel cells (PEFCs); however, they commonly confront a crucial issue of poor stability. Herein, a structural model of spatially confining supported Pt nanoparticles is determined to improve the stability of metal catalysts, wherein graphitic carbon nitride (gCN) supported Pt nanoparticles (gCN-Pt) are spatially confined by carbon nanospheres (CNSs). The resulting CNSs-Pt/gCN catalyst demonstrates a surprising retention rate of electrochemical surface area as high as 85.0%, much higher than that of the commercial Pt/C catalyst (45.2%), and the half-wave potential is reduced by only 11 mV compared with 54 mV for Pt/C after 6000 scanning cycles. In addition, CNSs also serve as a conductive agent to increase electron transfer pathways on Pt surfaces, and the unique spatial confinement structure with an open framework ensures the mass transfer. Moreover, the methanol oxidation reaction (MOR) activity of CNSs-Pt/gCN gets elevated by 2.1 times that of Pt/C in terms of the anodic peak current. The stabilized catalyst model and its derivative structures can be applied to various metal catalyst systems.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acsami.8b03832 | DOI Listing |
J Am Chem Soc
January 2025
State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou 350108, China.
Oxygen vacancies (OVs) spatially confined on the surface of metal oxide semiconductors are advantageous for photocatalysis, in particular, for O-involved redox reactions. However, the thermal annealing process used to generate surface OVs often results in undesired bulk OVs within the metal oxides. Herein, a high pressure-assisted thermal annealing strategy has been developed for selectively confining desirable amounts of OVs on the surface of metal oxides, such as tungsten oxide (WO).
View Article and Find Full Text PDFSci Rep
January 2025
Hangzhou Yanqu Information Technology Co., Ltd., Hangzhou, 310003, Zhejiang, China.
Electrocatalytic materials with dual functions of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) have received increasing attention in the field of zinc-air batteries (ZABs) research. In this study, bifunctional CoNC@NCXS catalysts were prepared by anchoring Co and N co-doped CoNC on N-doped carbon xerogel sphere (NCXS) based on the spatially confined domain effect and in-situ doping technique. CoNC@NCXS exhibited excellent ORR/OER activity in alkaline electrolytes with the ORR onset potential of 0.
View Article and Find Full Text PDFJ R Soc Interface
January 2025
Department of Engineering Mechanics, KTH Royal Institute of Technology, Stockholm, Sweden.
Culturing living cells in three-dimensional environments increases the biological relevance of laboratory experiments, but requires solutes to overcome a diffusion barrier to reach the centre of cellular constructs. We present a theoretical and numerical investigation that brings a mechanistic understanding of how microfluidic culture conditions, including chamber size, inlet fluid velocity and spatial confinement, affect solute distribution within three-dimensional cellular constructs. Contact with the chamber substrate reduces the maximally achievable construct radius by 15%.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai 201210, China.
The emergence of spinon quasiparticles, which carry spin but lack charge, is a hallmark of collective quantum phenomena in low-dimensional quantum spin systems. While the existence of spinons has been demonstrated through scattering spectroscopy in ensemble samples, real-space imaging of these quasiparticles within individual spin chains has remained elusive. In this study, we construct individual Heisenberg antiferromagnetic spin-1/2 chains using open-shell [2]triangulene molecules as building blocks.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Center for Sustainable Catalysis and Engineering, KU Leuven, Celestijnenlaan 200F, Leuven 3001, Belgium.
The local environment of the active site, such as the confinement of hydronium ions within zeolite pores, significantly influences catalytic turnover, similar to enzyme functionality. This study explores these effects in the hydrolysis of guaiacols─lignin-derived compounds─over zeolites in water. In addition to the interesting catechol products, this reaction is advantageous for study due to its bimolecular hydrolysis pathway, which involves a single energy barrier and no intermediates, simplifying kinetic studies and result interpretation.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!