Electrolyte contact changes nano-LiTiO bulk properties via surface polarons.

It is of general interest to combine the faradaic processes based high energy density of a battery with the non-faradaic processes based high power density of a capacitor in one cell. Surface area and functional groups of electrode materials strongly affect these properties. For the anode material LiTiO (LTO), we suggest a polaron based mechanism that influences Li ion uptake and mobility.

An electrochemical cell for in operando C nuclear magnetic resonance investigations of carbon dioxide/carbonate processes in aqueous solution.

In operando nuclear magnetic resonance (NMR) spectroscopy is one method for the online investigation of electrochemical systems and reactions. It allows for real-time observations of the formation of products and intermediates, and it grants insights into the interactions of substrates and catalysts. An in operando NMR setup for the investigation of the electrolytic reduction of at silver electrodes has been developed.

Overall Oxygen Electrocatalysis on Nitrogen-Modified Carbon Catalysts: Identification of Active Sites and In Situ Observation of Reactive Intermediates.

The recent mechanistic understanding of active sites, adsorbed intermediate products, and rate-determining steps (RDS) of nitrogen (N)-modified carbon catalysts in electrocatalytic oxygen reduction (ORR) and oxygen evolution reaction (OER) are still rife with controversy because of the inevitable coexistence of diverse N configurations and the technical limitations for the observation of formed intermediates. Herein, seven kinds of aromatic molecules with designated single N species are used as model structures to investigate the explicit role of each common N group in both ORR and OER. Specifically, dynamic evolution of active sites and key adsorbed intermediate products including O (ads), superoxide anion O *, and OOH* are monitored with in situ spectroscopy.

Heteronuclear cross-relaxation effect modulated by the dynamics of N-functional groups in the solid state under N DP-MAS DNP.

In a typical magic-angle spinning (MAS) dynamic nuclear polarization (DNP) nuclear magnetic resonance (NMR) experiment, several mechanisms are simultaneously involved when transferring much larger polarization of electron spins to NMR active nuclei of interest. Recently, specific cross-relaxation enhancement by active motions under DNP (SCREAM-DNP) [Daube et al. JACS 2016] has been reported as one of these mechanisms.

Non-Pairwise Interactions in Parahydrogen Experiments: Nuclear Exchange of Single Protons Enables Bulk Water Hyperpolarization.

Hyperpolarization with parahydrogen (p-H ) is a fast developing field in NMR, which enables overcoming the inherent low sensitivity of this important technique. The hyperpolarization of solvents, particularly of water, offers a wide range of applications for structural investigations of macromolecules and biomedical imaging. Until lately, only organic solvents could be polarized by means of parahydrogen via coherent redistribution of polarization (SABRE mechanism).

Nitrogen-Functionalized Hydrothermal Carbon Materials by Using Urotropine as the Nitrogen Precursor.

Nitrogen-containing hydrothermal carbon (N-HTC) materials of spherical particle morphology were prepared by means of hydrothermal synthesis with glucose and urotropine as precursors. The molar ratio of glucose to urotropine has been varied to achieve a continuous increase in nitrogen content. By raising the ratio of urotropine to glucose, a maximal nitrogen fraction of about 19 wt % could be obtained.

Hyperpolarizing Water with Parahydrogen.

Studies of water-based systems are of fundamental interest for nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) as water is the most abundant and important medium for global living. Hence, increasing the polarization of water and dissolved compounds is particularly attractive for biomedical applications such as investigations of intermolecular interactions and metabolite structures as well as for imaging purposes. In this work, we show a new approach based on para enriched hydrogen (p-H ) that enables the hyperpolarization of bulk water if a suitable catalytic system is employed.

A New Ir-NHC Catalyst for Signal Amplification by Reversible Exchange in D2 O.

NMR signal amplification by reversible exchange (SABRE) has been observed for pyridine, methyl nicotinate, N-methylnicotinamide, and nicotinamide in D2 O with the new catalyst [Ir(Cl)(IDEG)(COD)] (IDEG=1,3-bis(3,4,5-tris(diethyleneglycol)benzyl)imidazole-2-ylidene). During the activation and hyperpolarization steps, exclusively D2 O was used, resulting in the first fully biocompatible SABRE system. Hyperpolarized (1) H substrate signals were observed at 42.

A nanoparticle catalyst for heterogeneous phase para-hydrogen-induced polarization in water.

Para-hydrogen-induced polarization (PHIP) is a technique capable of producing spin polarization at a magnitude far greater than state-of-the-art magnets. A significant application of PHIP is to generate contrast agents for biomedical imaging. Clinically viable and effective contrast agents not only require high levels of polarization but heterogeneous catalysts that can be used in water to eliminate the toxicity impact.

Fundamental aspects of parahydrogen enhanced low-field nuclear magnetic resonance.

We report new phenomena in low-field 1H nuclear magnetic resonance (NMR) spectroscopy using parahydrogen induced polarization (PHIP), enabling determination of chemical shift differences, δν, and the scalar coupling constant J. NMR experiments performed with thermal polarization in millitesla magnetic fields do not allow the determination of scalar coupling constants for homonuclear coupled spins in the inverse weak coupling regime (δν View Article and Find Full Text PDF