Electrical reduction of perovskite electrodes for accelerating exsolution of nanoparticles

This work was supported through the Leading Graduate School Program: Academy for Co-creative Education of Environment and Energy Science (ACEEES) funded by the Ministry of Education, Culture, Sports, Science and Technology (MEXT, Japan).Growth of finely dispersed nanocatalysts by exsolution of metal nanoparticles from perovskite oxides under reducing conditions at elevated temperature is a promising approach of producing highly active catalytic materials. An alternative method of exsolution using an applied potential has been recently shown to potentially accelerate the exsolution process of nanoparticles that can be achieved in minutes rather than the hours required in chemical reduction. In the present study, we investigate exsolution of nanoparticles from perovskite oxides of La0.43Ca0.37Ni0.06Ti0.94O3-γ (LCTNi) and La0.43Ca0.37Ni0.03Fe0.03Ti0.94O3-γ (LCTNi-Fe) under applied potentials in carbon dioxide atmosphere. The impedance spectra of single cells measured before and after electrochemical poling at varying voltages showed that the onset of exsolution process occurred at 2 V of potential reduction. An average particle size of the exsolved nanoparticles observed after testing using a scanning electron microscopy was about 30–100 nm. The cells with the reduced electrodes exhibited desirable electrochemical performances not only in pure carbon dioxide (current density of 0.37 A cm−2 for LCTNi and 0.48 A cm−2 for LCTNi-Fe at 1.5 V) but also in dry hydrogen (0.36 W cm−2 for LCTNi and 0.43 W cm−2 for LCTNi-Fe).PostprintPeer reviewe

Metal-oxide interactions for infiltrated Ni nanoparticles on A-site deficient LaxSr1 − 3x/2TiO3

The authors would like to thank EPSRC Platform (Grant EP/K015540/1) and the Royal Society for Wolfson Merit Award (WRMA 2012/R2) for funding. We also acknowledge support from China Scholarship Council (No. 201406690029).Enhancing the stability of introduced metal catalysts on oxide surfaces is a major issue for infiltrated anodes in Solid Oxide Cells (SOC) and other related catalysis field. Stoichiometric SrTiO3 (STO) and A-site cation deficient LaxSr1 − 3x/2TiO3 (LST) were compared to investigate the influence of stoichiometry upon the contact between metal and oxide, in order to improve the bonding of catalyst and substrate. Optimization of oxidizing and reducing temperatures for Ni infiltration processes was performed to get good nanoparticles distribution on the perovskite surface. Thermogravimetry (TG) and X-ray diffraction (XRD) analysis showed the formation of NiO, Ni after oxidation and reduction, respectively. Energy Dispersive Spectroscopy (EDS) on a Transmission Electron Microscopy (TEM) was employed to characterize the nickel nanoparticles on the LST surface. No obvious elemental transfer happened between Ni and LST. The TEM images showed Ni nanoparticles bonded well to the A-site deficient perovskite with large contact area. TG analysis in reducing atmosphere indicates interactions between metal-oxide interactions in deficient samples. This may improve the Ni distribution on perovskite surface and further control the growth of Ni particles when heated at extreme temperature.PostprintPeer reviewe

Experimental study on the influence of middle and low rank coal functional groups on coal wettability

Coal seam water injection can effectively inhibit gas gushing in the process of coal mining, and its inhibition effect mainly depends on the wetting characteristics of coal seam. The chemical structure of coal is one of the important factors affecting the wettability of coal. In order to study the relationship between the functional groups of medium and low rank coal and its wettability, the coal quality characteristics of typical medium and low rank coal samples were analyzed, and the parameters of different coal samples were obtained by Nicolet iN10 Fourier Transform microscopic infrared spectrometer. In this paper, the size of the contact Angle of deionized water at the solid-liquid-gas junction on the coal surface is used to characterize the wettability of coal. JC2000D contact Angle measuring instrument is used to obtain the contact Angle of different coal samples. Zeta potential can reflect wettability and ionization degree of coal surface functional groups, so as to establish the relationship between hydrophilic functional groups (hydroxyl functional groups, other oxygen-containing functional groups), contact Angle and Zeta potential of coal samples. The experimental results show that with the deepening of coal metamorphism, the strength of hydrophilic functional groups of coal samples decreases gradually, the peak height of hydrophilic functional groups of middle rank coal decreases by 0.13 compared with that of low rank coal, and the absorption peak area decreases by 58.91. The hydrophilic functional groups are negatively correlated with the contact Angle of coal samples, that is, the contact Angle decreases gradually with the increase of absorption peak intensity of hydrophilic functional groups, and the contact Angle decreases by 8.27 ° from middle rank coal samples to low rank coal samples. The relationship between hydrophilic functional groups and Zeta potential of coal samples shows a first-order exponential decay function, and the correlation coefficient is as high as 0.95. That is to say, the absolute value of Zeta potential increases gradually with the increase of absorption peak area of hydrophilic functional groups. The surface electronicity of coal samples is strong, and the hydrophilicity of coal is good. Among them, the hydroxyl functional group has a great influence on the wettability of coal, and the hydrogen bond formed by self-associating hydroxyl group is the main factor affecting the wettability of coal. Other oxygen-containing functional groups, such as carboxyl and ether bond hydrophilic functional groups, combine with water molecules under intermolecular force, showing strong vitality and improving the hydrophilicity of coal

Patient safety culture in private hospitals in China: a cross-sectional study using the revised Hospital Survey on Patient Safety Culture

BackgroundThis study aimed to translate the revised Hospital Survey on Patient Safety Culture (HSOPSC 2.0) to Mandarin, evaluate its psychometric properties, and apply it to a group of private hospitals in China to identify the determinants associated with patient safety culture.MethodsA two-phase study was conducted to translate and evaluate the HSOPSC 2.0. A cross-cultural adaptation of the HSOPSC 2.0 was performed in Mandarin and applied in a cross-sectional study in China. This study was conducted among 3,062 respondents from nine private hospitals and 11 clinics across six cities in China. The HSOPSC 2.0 was used to assess patient safety culture. Primary outcomes were measured by the overall patient safety grade and patient safety events reported.ResultsConfirmatory factor analysis results and internal consistency reliability were acceptable for the translated HOSPSC 2.0. The dimension with the highest positive response was “Organizational learning - Continuous improvement” (89%), and the lowest was “Reporting patient safety event” (51%). Nurses and long working time in the hospital were associated with lower assessments of overall patient safety grades. Respondents who had direct contact with patients, had long working times in the hospital, and had long working hours per week reported more patient safety events. A higher level of patient safety culture implies an increased probability of a high overall patient safety grade and the number of patient safety events reported.ConclusionThe Chinese version of HSOPSC 2.0 is a reliable instrument for measuring patient safety culture in private hospitals in China. Organizational culture is the foundation of patient safety and can promote the development of a positive safety culture in private hospitals in China