Reactivity of nitrogen atoms from Zif-8 structure deposited over TiC MXene in the electrochemical nitrogen reduction reaction.

The electrochemical nitrogen reduction reaction (NRR) to produce NH is the most efficient, eco-friendly and cost-effective alternative to the Haber-Bosch process. It is crucial to investigate and develop electrocatalysts selective for NH synthesis. In recent studies, the TiC MXene has emerged as a highly promising electrocatalyst for the NRR process.

Operando Isotopic Exchange in Solid Oxide Fuel Cells: Oxygen-Transport Dependency on Applied Potential.

The oxygen isotopic exchange technique is a powerful tool to investigate the oxygen transport kinetics in an oxide solid. In a solid oxide fuel cell, isotopic surface exchange and diffusion coefficients are classically determined by using the Isotopic Exchange Depth Profiling method followed by ex situ SIMS characterizations. Despite its relevance, the utilization of in situ or operando techniques to measure the isotopic exchange under an electrical bias remains marginal.

Palladium, Iridium, and Rhodium Supported Catalysts: Predictive H₂ Chemisorption by Statistical Cuboctahedron Clusters Model.

Chemisorption of hydrogen on metallic particles is often used to estimate the metal dispersion (), the metal particle size (), and the metallic specific surface area (), currently assuming a stoichiometry of one hydrogen atom adsorbed per surface metal atom . This assumption leads to a large error when estimating , , and , and a rigorous method is needed to tackle this problem. A model describing the statistics of the metal surface atom and site distribution on perfect cuboctahedron clusters, already developed for Pt, is applied to Pd, Ir, and Rh, using the density functional theory (DFT) calculation of the literature to determine the most favorable adsorption sites for each metal.

One-Pot Soft-Template Synthesis of Nanostructured Copper-Supported Mesoporous Carbon FDU-15 Electrocatalysts for Efficient CO Reduction.

Copper-supported mesoporous carbon nanocatalysts (Cu/FDU-15) were synthesized using an easy and convenient one-pot soft-template method for low-overvoltage CO electroreduction. TEM imaging revealed the presence of large Cu nanoparticles (diameter 140 nm) with Cu O nanoparticles (16 nm) as an additional phase. From the electron tomography observations, we found that the copper particles were placed inside and on the exterior surface of the porous FDU-15 support, providing an accessible surface for electrocatalytic reactions.

Catalysis and Inhibition in the Electrochemical Reduction of CO on Platinum in the Presence of Protonated Pyridine. New Insights into Mechanisms and Products.

In the framework of modern energy challenges, the reduction of CO into fuels calls for electrogenerated low-valent transition metal complexes catalysts designed with considerable ingenuity and sophistication. For this reason, the report that a molecule as simple as protonated pyridine (PyH) could catalyze the formation of methanol from the reduction of CO on a platinum electrode triggered great interest and excitement. Further investigations revealed that no methanol is produced.

Efficient electrolyzer for CO2 splitting in neutral water using earth-abundant materials.

Low-cost, efficient CO2-to-CO+O2 electrochemical splitting is a key step for liquid-fuel production for renewable energy storage and use of CO2 as a feedstock for chemicals. Heterogeneous catalysts for cathodic CO2-to-CO associated with an O2-evolving anodic reaction in high-energy-efficiency cells are not yet available. An iron porphyrin immobilized into a conductive Nafion/carbon powder layer is a stable cathode producing CO in pH neutral water with 90% faradaic efficiency.

Multichannel bipotentiostat integrated with a microfluidic platform for electrochemical real-time monitoring of cell cultures.

An electrochemical detection system specifically designed for multi-parameter real-time monitoring of stem cell culturing/differentiation in a microfluidic system is presented. It is composed of a very compact 24-channel electronic board, compatible with arrays of microelectrodes and coupled to a microfluidic cell culture system. A versatile data acquisition software enables performing amperometry, cyclic voltammetry and impedance spectroscopy in each of the 12 independent chambers over a 100 kHz bandwidth with current resolution down to 5 pA for 100 ms measuring time.

Electrochemical determination of pKa of N-bases in ionic liquid media.

Two electrochemical techniques have been used to measure the pK(a) of N-bases in several ionic liquids (ILs). The first method corresponds to a potentiometric titration of a strong acid with the N-base using a platinized Pt indicator electrode immersed in the IL solution and maintained under dihydrogen atmosphere via gas bubbling. The second approach involves performing cyclic voltammetry at a platinized Pt electrode in a solution containing both strong acid and the conjugate weak acid of the N-base.

Mechanism of 2,2'6,6'-tetramethylpiperidin-N-oxyl-mediated oxidation of alcohols in ionic liquids.

The mechanism of 2,2'6,6'-tetramethylpiperidin- N-oxyl (TEMPO)-mediated oxidation of alcohols to aldehydes and ketones in ionic liquids has been investigated using cyclic voltammetry and rotating disk electrode voltammetry. It is shown that the presence of bases (B) and their conjugate acids (BH (+)), as well as their p K as, strongly influences the rate of reaction. Data indicated that the first step in the oxidation is the formation of the alcoholate species via acid-base equlibrium with B.