High Throughput In Situ XAFS Screening of Catalysts

We outline and demonstrate the feasibility of high-throughput (HT) in situ XAFS for synchrotron radiation studies. An XAS data acquisition and control system for the analysis of dynamic materials libraries under control of temperature and gaseous environments has been developed. The system is compatible with the 96-well industry standard and coupled to multi-stream quadrupole mass spectrometry (QMS) analysis of reactor effluents. An automated analytical workflow generates data quickly compared to traditional individual spectrum acquisition and analyses them in quasi-real time using an HT data analysis tool based on IFFEFIT. The system was used for the automated characterization of a library of 91 catalyst precursors containing ternary combinations of Cu, Pt, and Au on ?-Al2O3, and for the in situ characterization of Au catalysts supported on Al2O3 and TiO2

Preconditioning with Physiological Levels of Ethanol Protect Kidney against Ischemia/Reperfusion Injury by Modulating Oxidative Stress

Oxidative stress due to excessive production of reactive oxygen species (ROS) and subsequent lipid peroxidation plays a critical role in renal ischemia/reperfusion (IR) injury. The purpose of current study is to demonstrate the effect of antecedent ethanol exposure on IR-induced renal injury by modulation of oxidative stress.Bilateral renal warm IR was induced in male C57BL/6 mice after ethanol or saline administration. Blood ethanol concentration, kidney function, histological damage, inflammatory infiltration, cytokine production, oxidative stress, antioxidant capacity and Aldehyde dehydrogenase (ALDH) enzymatic activity were assessed to evaluate the impact of antecedent ethanol exposure on IR-induced renal injury.After bilateral kidney ischemia, mice preconditioned with physiological levels of ethanol displayed significantly preserved renal function along with less histological tubular damage as manifested by the reduced inflammatory infiltration and cytokine production. Mechanistic studies revealed that precondition of mice with physiological levels of ethanol 3 h before IR induction enhanced antioxidant capacity characterized by significantly higher superoxidase dismutase (SOD) activities. Our studies further demonstrated that ethanol pretreatment specifically increased ALDH2 activity, which then suppressed lipid peroxidation by promoting the detoxification of Malondialdehyde (MDA) and 4-hydroxynonenal (HNE).Our results provide first line of evidence indicating that antecedent ethanol exposure can provide protection for kidneys against IR-induced injury by enhancing antioxidant capacity and preventing lipid peroxidation. Therefore, ethanol precondition and ectopic ALDH2 activation could be potential therapeutic approaches to prevent renal IR injury relevant to various clinical conditions

The hydration structure of Cu2+: more tetrahedral than octahedral?

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.A comprehensive multi-technique approach has been used to address the controversial question of the preferred geometric form of the Cu2+ aqua-ion hydration shell. A combination of H/D isotopic substitution neutron scattering and X-ray scattering has been used to refine atomistic models of 0.5 m and 2.0 m solutions of Cu(ClO4)2, that have also been constrained to simultaneously reproduce detailed local structure information about the cation environment obtained by X-ray Absorption spectroscopy. The adoption of the Empirical Potential Structure Refinement (EPSR) technique as a single unified analytical framework minimises the chances for biasing the result in favour of a specific pre-conceived outcome. The results are consistent with an average coordination for each Cu2+ ion of 4.5 ± 0.6 water molecules that matches the more recent picture of five-fold coordination in a 2.0 m solution, but interestingly this combined study highlights that the preferred local geometry of the ion sites is found to have a mixed character of tetrahedral, trigonal bipyramidal and octahedral components. A further point to note is that this new model adds support to a largely ignored result in the literature relating to the linear electric field effect induced g-shifts observed in the electron paramagnetic resonance spectra of glassy Cu 2+ complexes (Peisach and Mims, Chem. Phys. Lett., 1976, 37, 307-310) that first highlighted the importance of tetrahedral distortions in the cation's hydration shell structure. This journal is © The Royal Society of Chemistry.RB acknowledges support from the Ministerio de Economía y Competitividad of Spain.We would like to thank Red de Bibliotecas del CSIC for their support to publish this work in open format.Peer Reviewe

Dataset for 'The electronic structure, surface properties, and in situ N2O decomposition of mechanochemically synthesised LaMnO3'

This dataset supports the publication: Rachel H. Blackmore, Maria Elena Rivas, George Tierney, Khaled M. H. Mohammed, Donato Decarolis, Shusaku Hayama, Federica Venturini, Georg Held, Rosa Arrigo, Monica Amboage, Pip Hellier, Evan Lynch, Mahrez Amri, Marianna Casavola, Tugce Eralp Erden, Paul Collier and Peter P. Wells. The electronic structure, surface properties, and in situ N2O decomposition of mechanochemically synthesised LaMnO3. Physical Chemistry Chemical Physics Journal (PCCP)</span

High-throughput structure/function screening of materials and catalysts with multiple spectroscopic techniques

High throughput screening methodologies are expanded to synchrotron based x-ray absorption techniques. An environmental chamber, based on ultra-high vacuum equipment, has been developed allowing in situ studies on arrays of samples while X-ray absorption fine structure spectroscopy, Raman spectroscopy, mass spectrometry and/or Xray diffraction can be applied simultaneously to characterize the system under process conditions in a time-resolved manner. The chamber accommodates a diverse range of samples from surface science to materials chemistry to heterogeneous catalysis. Data acquisition and data logging software is developed to handle large quantities of divers but related information. New data logging, processing and analysis procedures and programs are developed which will allow fast structure-function relationships characterization