Most NMR samples are cylindrical, which is ideal for obtaining high-resolution NMR spectra, especially in superconducting magnets with a vertical bore. However, expanding NMR applicability to samples that are not necessarily cylindrical requires a new approach. In this study, we introduce a method for obtaining solution NMR signals from flat samples, such as flat containers or layered structures like a fuel cell. A flat rectangular NMR coil was developed for RF application and sensitive signal detection, while biplanar shim coils were designed using Bfieldtools and manufactured on multilayered printed circuit boards to improve NMR resolution. Water and ethanol molecules in flat rectangular and flat circular containers, as well as in a direct ethanol fuel cell, were observed with narrow NMR linewidths. We believe that our spectrometer design will enable NMR analysis of samples that need to be contained in flat structures and support in-situ analysis of various devices.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jmr.2025.107831DOI Listing

Publication Analysis

Top Keywords

fuel cell
12
nmr signals
8
samples flat
8
in-situ analysis
8
direct ethanol
8
ethanol fuel
8
nmr
8
samples cylindrical
8
flat rectangular
8
flat
7

Similar Publications

Dissociation of hydrogen and formation of water at the (010) and (111) surfaces of orthorhombic FeNbO4.

Chemphyschem

January 2025

University of Leeds, School of Chemistry, Woodhouse Lane, LS2 9JT, Leeds, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND.

The orthorhombic structure of FeNbO4, where the Fe and Nb cations are distributed randomly over the octahedral 4c sites, has shown excellent promise as an anode material in solid oxide fuel cells. We have used DFT+U-D2 calculations to explore the adsorption and dissociation of H2 molecules and the formation reaction of water at the (010) and (111) surfaces. Simulations of the surface properties confirmed that the bandgaps are significantly reduced compared to the bulk material.

View Article and Find Full Text PDF

Direct formate fuel cells (DFFCs) have received increasing attention due to their environmentally benign and highly safe characteristics. However, the absence of highly active electrocatalysts for the formate oxidation reaction (FOR) restricts their widespread application. Currently, the design of FOR catalysts, which relies on experimental trial-and-error and high-throughput DFT calculations, is costly and time-consuming.

View Article and Find Full Text PDF

The two-dimensional lamellar materials disperse platinum sites and minimize noble-metal usage for fuel cells, while mass transport resistance at the stacked layers spurs device failure with a significant performance decline in membrane electrode assembly (MEA). Herein, we implant porous and rigid sulfonated covalent organic frameworks (COF) into the graphene-based catalytic layer for the construction of steric mass-charge channels, which highly facilitates the activity of oxygen reduction reactions in both the rotating disk electrode (RDE) measurements and MEA device tests. Specifically, the normalized mass activity is remarkably boosted by 3.

View Article and Find Full Text PDF

Template-free synthesis of a multilayer manganese oxide/graphene oxide nanoflake-modified carbon felt as an anode material for microbial fuel cells.

RSC Adv

January 2025

CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences Chengdu 610041 China.

A novel multilayer nanoflake structure of manganese oxide/graphene oxide (γ-MnO/GO) was fabricated a simple template-free chemical precipitation method, and the modified carbon felt (CF) electrode with γ-MnO/GO composite was used as an anode material for microbial fuel cells (MFCs). The characterization results revealed that the γ-MnO/GO composite has a novel multilayer nanoflake structure and offers a large specific surface area for bacterial adhesion. The electrochemical analyses demonstrated that the γ-MnO/GO composite exhibited excellent electrocatalytic activity and enhanced the electrochemical reaction rate and reduced the electron transfer resistance, consequently facilitating extracellular electron transfer (EET) between the anode and bacteria.

View Article and Find Full Text PDF

Microbial fuel cells (MFCs) have garnered significant attention from researchers as an innovative and environmentally friendly method for the treatment of urban and industrial wastewater. The type and material of the electrode are critical factors affecting the efficiency and energy production of this process. The electrodeposition method was employed to dope nickel (Ni) and modify the surface of graphite plates (GP) and carbon felt (CF).

View Article and Find Full Text PDF

Want 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!