Nanoparticulate TiO2-promoted PtRu/C catalyst for methanol oxidation: TiO2 nanoparticles promoted PtRu/C catalyst for MOR

To improve the electrocatalytic properties of PtRu/C in methanol electrooxidation, nanoparticulate TiO2-promoted PtRu/C catalysts were prepared by directly mixing TiO2 nanoparticles with PtRu/C. Using cyclic voltammetry, it was found that the addition of 10 wt% TiO2 nanoparticles can effectively improve the electrocatalytic activity and stability of the catalyst during methanol electro-oxidation. The value of the apparent activation energy (Ea) for TiO2-PtRu/C was lower than that for pure PtRu/C at a potential range from 0.45 to 0.60 V. A synergistic effect between PtRu and TiO2 nanoparticles is likely to facilitate the removal of CO-like intermediates from the surface of PtRu catalyst and reduce the poisoning of the PtRu catalysts during methanol electrooxidation. Therefore, we conclude that the direct introduction of TiO2 nanoparticles into PtRu/ C catalysts offers an improved facile method to enhance the electrocatalytic performance of PtRu/C catalyst in methanol electrooxidation.Web of Scienc

Influence of <i>p</i>H<i> </i>and supporting electrolyte on electrochemical reduction of CO₂ using nickel(II) macrocyclic complex of 1, 3, 6, 9, 11, 14 - hexaazacyclohexadecane as catalyst at HMDE

472-477Electrochemical studies on the title compound using cyclic voltammogram (CV) and control potential electrolysis (CPE) techniques reveal that it reduces CO2 electrocatalytically at -1.36V /SCE at hanging mercury drop electrode (HMDE) in aqueous medium using LiClO4 as a supporting electrolyte. The products are found to be CO and H2 in 3:2 mole ratio in the gaseous phase as detected using gas chromatography (GC) and trace amounts of formic acid in solution phase as detected using colorimetric technique. The Ik / Id values (where Ik is the kinetic current measured in the presence of CO2 and Id is the diffusion current measured in N2 atmosphere) observed at various pH values show that pH 5.0 is best suited for CO2 reduction. In addition, the hydrophobicity/hydrophilicity near the electrode surface provided by the cation of the supporting salt and its influence on CO2 reduction is discussed

3₁₀ helix formation in protected tripeptide

The conformational analysis of a synthetic peptide Boc-Lys(Z)-Gly-Val-NHMe has been carried out, as a model for nucleating segment in helix formation. 1H NMR studies (270 MHz) suggested that the Gly (2) NH, Val (3) NH and NHMe groups are solvent shielded. Conformational energy calculations and intramolecular hydrogen bonding constrains favour 310 helix structure for the peptide. Theoretical and spectroscopic results are consistent with the presence of a transannular 4 -> 1 hydrogen bond between Lys (1) CO and NHMe with Gly (2) NH and Val (3) being sterically shielded from the solvent environment