Controlling the Reaction Pathways of Mixed NOH Reactants in Plasma-Electrochemical Ammonia Synthesis.

Electrochemical activation of dinitrogen (N) is notoriously challenging, typically yielding very low ammonia (NH) production rates. In this study, we present a continuous flow plasma-electrochemical reactor system for the direct conversion of nitrogen from air into ammonia. In our system, nitrogen molecules are first converted into a mixture of NO species in the plasma reactor, which are then fed into an electrochemical reactor.

Distribution characteristics of Purkinje fibres in the canine left ventricle.

Purkinje-related ventricular arrhythmias have been increasingly reported, and with the development of catheter ablation techniques, intervention for Purkinje-related arrhythmias has been shown to be effective. The characteristics of Purkinje fibres orientation in the 12 canine left ventricles were observed at a gross level by staining the endocardium with Lugol's solution. Purkinje fibres were observed microscopically by HE, Masson's, PAS glycogen, and Cx40 immunohistochemical staining.

Electrocatalytic Production of Hydrogen Peroxide Enabled by Post-Synthetic Modification of a Self-Assembled Porphyrin Cube.

Self-assembled metallacyles and cages formed via coordination chemistry have been used as catalysts to enforce 4H/4e reduction of oxygen to water with an emphasis on attenuating the formation of hydrogen peroxide. That said, the kinetically favored 2H/2e reduction to HO is critically important to industry. In this work we report the synthesis, characterization, and electrochemical benchmarking of a hexa-porphyrin cube which catalyses the electrochemical reduction of molecular oxgyen to hydrogen peroxide.

The rigidity of self-assembled cofacial porphyrins influences selectivity and kinetics of oxygen reduction electrocatalysis.

We report the electrocatalytic Oxygen Reduction Reaction on a rigid Co(II) porphyrin prism scaffold bridged by Ag(I) ions. The reactivity of this scaffold differs significantly from previous prism catalysts in that its selectivity is similar to that of monomer (∼35% HO) yet it displays sluggish kinetics, with an order of magnitude lower of ∼0.5 M s.

Lowering the Symmetry of Cofacial Porphyrin Prisms for Selective Oxygen Reduction Electrocatalysis.

Cofacial porphyrin catalysts for the Oxygen Reduction Reaction (ORR) formed via coordination-driven self-assembly have so far been limited to designs with fourfold symmetry, where four molecular clips bridge two porphyrin sites. We have synthesized six PyPh (Py = pyridyl, Ph = phenyl) metalloporphyrin prisms (Co, Zn) bridged by molecular clips containing two Rh centers. Four of these structures are lower symmetry, with the PyPh and PyPh prisms containing three and two molecular clips, respectively.

Tuning the Reactivity of Cofacial Porphyrin Prisms for Oxygen Reduction Using Modular Building Blocks.

We assembled eight cofacial porphyrin prisms using MTPyP (M = Co(II) or Zn(II), TPyP = 4-tetrapyridylporphyrin) and functionalized ruthenium-based "molecular clips" using coordination-driven self-assembly. Our approach allows for the rapid synthesis of these architectures in isolated yields as high as 98% for the assembly step. Structural and reactivity studies provided a deeper understanding of the role of the building blocks on the oxygen reduction reaction (ORR).