Boosting hot electron flux and catalytic activity at metal-oxide interfaces of PtCo bimetallic nanoparticles

Despite numerous studies, the origin of the enhanced catalytic performance of bimetallic nanoparticles (NPs) remains elusive because of the ever-changing surface structures, compositions, and oxidation states of NPs under reaction conditions. An effective strategy for obtaining critical clues for the phenomenon is real-time quantitative detection of hot electrons induced by a chemical reaction on the catalysts. Here, we investigate hot electrons excited on PtCo bimetallic NPs during H-2 oxidation by measuring the chemicurrent on a catalytic nanodiode while changing the Pt composition of the NPs. We reveal that the presence of a CoO/Pt interface enables efficient transport of electrons and higher catalytic activity for PtCo NPs. These results are consistent with theoretical calculations suggesting that lower activation energy and higher exothermicity are required for the reaction at the CoO/Pt interface

Monitoring Real-time Dynamics of Nanoparticle Formation via ‘Trading Space with Time’ Strategy and Synchrotron X-ray Absorption Spectroscopy Technique

International audienc

In Situ Microscopy and Spectroscopy Applied to Surfaces at Work

The present review discusses the current state of the art microscopic and spectroscopic characterization techniques available to study surfaces and interfaces under working conditions. Microscopic techniques such as environmental transmission electron microscopy and in situ transmission electron microscopy are first discussed showing their applications in the field of nanomaterials and catalysis. Next sum frequency generation vibrational spectroscopy is discussed, giving probing examples of surface studies in gaseous conditions. Synchrotron based X-ray techniques are also examined with a specific focus on ambient pressure X-ray photoelectron and absorption techniques such as near and extended X-ray absorption fine structure. Each of the techniques is evaluated, whilst the pros and cons are discussed in term of surface sensitivity, spatial resolution and/or time resolution. The second part of the articles is articulated around the future of in situ characterization, giving examples of the probable development of the discussed techniques as well as an introduction of emerging tools such as scanning transmission X-ray microscopy, ptychography, and X-ray photon correlation spectroscopy

In Situ Microscopy and Spectroscopy Applied to Surfaces at Work

The present review discusses the current state of the art microscopic and spectroscopic characterization techniques available to study surfaces and interfaces under working conditions. Microscopic techniques such as environmental transmission electron microscopy and in situ transmission electron microscopy are first discussed showing their applications in the field of nanomaterials and catalysis. Next sum frequency generation vibrational spectroscopy is discussed, giving probing examples of surface studies in gaseous conditions. Synchrotron based X-ray techniques are also examined with a specific focus on ambient pressure X-ray photoelectron and absorption techniques such as near and extended X-ray absorption fine structure. Each of the techniques is evaluated, whilst the pros and cons are discussed in term of surface sensitivity, spatial resolution and/or time resolution. The second part of the articles is articulated around the future of in situ characterization, giving examples of the probable development of the discussed techniques as well as an introduction of emerging tools such as scanning transmission X-ray microscopy, ptychography, and X-ray photon correlation spectroscopy

Health services management in Turkey: Failure or success?

Background: The unfair distribution and delivery of health-care resources have been recognized as a problem in the worldwide. In the past 18 years, Turkey has undergone rapid social, cultural, and economic changes. The lifestyle and dietary habits of its people have also been changing, and the rates of diabetes, obesity, cancer, and other chronic diseases have increased dramatically over the past two decades. The health transformation program (HTP) has improved the Turkish health-care system since 2003. The main goal of HTP was to progress government, to provide equality between citizens, to give satisfaction to users and providers, and to subsidise the health-care system in Turkey. Aim: The aim of this study is to assess health-care services and health care quality delivery in the Republic of Turkey with special emphasis on governmental hospitals, university hospitals, primary healthcare centers (PHC) and to make comparison with low-, medium- and high-income countries. Methods: This is a retrospective, descriptive study. The ministry of health Annual Reports, websites of the Central Intelligence Agency (CIA), The World Fact Book, organization for economic cooperation and development report, Compendium of Health Statistics, the Google engine, and PubMed were searched for information about Turkey's health-care system and its history. Papers and websites in English were evaluated. There was no restriction on types of articles and sources. Results: Turkey has made outstanding reforms in health status in the last two decades, especially after the implementation of the HTP. The doctor's perception has more influence regarding consultation length and visit than the patient's. The results of consultations in volunteer practices in Istanbul showed that the mean and SD of the consultation length for the whole sample of 360 patients was 7.95 ± 4.38, (with range = 3–25 min). Consultation time has been affected by the patients' diseases, genders that women got longer consultation time, medical practices at the urban or rural areas, and ages which older patients required longer consultation time. The current study revealed that increasing doctor's workload leads to decrease the length of consultations. Moreover, average life expectancy reached 75.3 for men and 80.7 for women in 2015. The infant mortality rate decreased to 10.7/1000 live births in 2015, down from 117.5 in 1980. The leading causes of death are diseases of the circulatory system followed by cancer. Conclusions: The Turkish health system and health-care delivery have been improved over the last decade. Still far from perfect, there is a particular planning to increase medical workforce in PHC including well-trained staffs for a specific area. An urgent need is to acquire more accurate and reliable data from hospital and PHC centers in Turkey. Additional some attempts should be made to assess quality of healthcare in relation to services and process

High Structure Sensitivity of Vapor-Phase Furfural Decarbonylation/Hydrogenation Reaction Network as a Function of Size and Shape of Pt Nanoparticles

Vapor-phase transformations of furfural in H 2 over a series of Pt nanoparticles (NPs) with various particle sizes (1.5-7.1 nm size range) and shapes (rounded, cubes, octahedra) encapsulated in poly(vinylpyrrolidone) (PVP) and dispersed on MCF-17 mesoporous silica were investigated at ambient pressure in the 443-513 K temperature range. Furan and furfuryl alcohol (FFA) were two primary products as a result of furfural decarbonylation and hydrogenation reactions, respectively. Under conditions of the study both reactions exhibited structure sensitivity evidenced by changes in product selectivities, turnover rates (TORs), and apparent activation energies (E A's) with Pt particle size and shape. For instance, upon an increase in Pt particle size from 1.5 to 7.1 nm, the selectivity toward FFA increases from 1% to 66%, the TOR of FFA production increases from 1 ?? 10 -3 s -1 to 7.6 ?? 10 -2 s -1, and E A decreases from 104 kJ mol -1 to 15 kJ mol -1 (9.3 kPa furfural, 93 kPa H 2, 473 K). Conversely, under the same experimental conditions the decarbonylation reaction path is enhanced over smaller nanoparticles. The smallest NPs (1.5 nm) produced the highest selectivity (96%) and highest TOR values (8.8 ?? 10 -2 s -1) toward furan formation. The E A values for decarbonylation (???62 kJ mol -1) was Pt particle size independent. Furan was further converted to propylene via a decarbonylation reaction, but also to dihydrofuran, tetrahydrofuran, and n-butanol in secondary reactions. Furfuryl alcohol was converted to mostly to 2-methylfuran. © 2012 American Chemical Society.close383

Health Services Management in Turkey: Failure or Success?

Background: The unfair distribution and delivery of health-care resources have been recognized as a problem in the worldwide. In the past 18 years, Turkey has undergone rapid social, cultural, and economic changes. The lifestyle and dietary habits of its people have also been changing, and the rates of diabetes, obesity, cancer, and other chronic diseases have increased dramatically over the past two decades. The health transformation program (HTP) has improved the Turkish health-care system since 2003. The main goal of HTP was to progress government, to provide equality between citizens, to give satisfaction to users and providers, and to subsidise the health-care system in Turkey. Aim: The aim of this study is to assess health-care services and health care quality delivery in the Republic of Turkey with special emphasis on governmental hospitals, university hospitals, primary healthcare centers (PHC) and to make comparison with low-, medium- and high-income countries. Methods: This is a retrospective, descriptive study. The ministry of health Annual Reports, websites of the Central Intelligence Agency (CIA), The World Fact Book, organization for economic cooperation and development report, Compendium of Health Statistics, the Google engine, and PubMed were searched for information about Turkey's health-care system and its history. Papers and websites in English were evaluated. There was no restriction on types of articles and sources. Results: Turkey has made outstanding reforms in health status in the last two decades, especially after the implementation of the HTP. The doctor's perception has more influence regarding consultation length and visit than the patient's. The results of consultations in volunteer practices in Istanbul showed that the mean and SD of the consultation length for the whole sample of 360 patients was 7.95 +/- 4.38, (with range = 3-25 min). Consultation time has been affected by the patients' diseases, genders that women got longer consultation time, medical practices at the urban or rural areas, and ages which older patients required longer consultation time. The current study revealed that increasing doctor's workload leads to decrease the length of consultations. Moreover, average life expectancy reached 75.3 for men and 80.7 for women in 2015. The infant mortality rate decreased to 10.7/1000 live births in 2015, down from 117.5 in 1980. The leading causes of death are diseases of the circulatory system followed by cancer. Conclusions: The Turkish health system and health-care delivery have been improved over the last decade. Still far from perfect, there is a particular planning to increase medical workforce in PHC including well-trained staffs for a specific area. An urgent need is to acquire more accurate and reliable data from hospital and PHC centers in Turkey. Additional some attempts should be made to assess quality of healthcare in relation to services and process