Potential-Rate Correlations of Supported Palladium-Based Catalysts for Aqueous Formic Acid Dehydrogenation.

Aqueous formic acid dehydrogenation (FAD) is a crucial process for hydrogen production, as hydrogen is a clean energy carrier. During this process, formic acid converts into hydrogen and carbon dioxide over a catalyst. Pd-based catalysts have exhibited significant potential in FAD due to their high activity and selectivity. In this study, we investigated aqueous thermal FAD in a mixture of formic acid and sodium formate using electrochemical open-circuit potential (OCP) measurement by loading the catalysts onto a conductive substrate as a working electrode. By varying the reaction conditions such as the concentration of reactants and modifying Pd with Ag, different FAD rates were obtained. Consequently, we revealed the correlation between the catalyst OCP and FAD rate; superior FAD rates reflected a more negative catalyst OCP. Furthermore, deactivation was observed across all catalysts during FAD, with a concurrent increase in catalyst OCP. Interestingly, we found that the logarithm of the FAD rate showed a linear correlation with the OCP of the catalyst during the decay phase, which we quantitatively explained based on the reaction mechanism. This study presents a new discovery that bridges thermal and electrocatalysis.

Geriatric Nutritional Risk Index Predicts High Activities of Daily Living at Discharge in Older Patients with Heart Failure after Cardiac Rehabilitation.

BACKGROUND: Hospitalization often leads to a decline in activities of daily living (ADL) in older patients with heart failure. Although cardiac rehabilitation (CR) improves ADL, it can be difficult to perform CR due to the deconditioning of these patients. This study aimed to examine the factors associated with ADL at discharge in older patients with heart failure who underwent CR. METHODS: A total of 86 of 110 older heart failure patients aged ≥ 75 years (average age, 86.9 ± 5.7 years) transferred to our institution for CR were enrolled and classified into high ADL at discharge (n = 54) and low ADL at discharge (n = 32) groups. Physical characteristics, comorbidities, medications, blood test data, echocardiographic data, and nutritional status (Geriatric Nutritional Risk Index [GNRI]) were retrospectively examined from medical records. ADL were assessed using the Barthel Index (BI) at admission and discharge. Considering multicollinearity, the relationship between high ADL (BI ≥ 60) at discharge and these assessments at admission was analyzed using multiple logistic regression analysis. The receiver operating characteristic curve was analyzed to calculate the cutoff values for the parameters identified by the multiple logistic regression analysis. RESULTS: The GNRI was the only independent factor predicting high ADL at discharge (p = 0.041; odds ratio [OR], 1.125; 95% confidence interval [CI], 1.005-1.260). The area under the receiver operating characteristic curve for the GNRI was 0.770 (95% CI, 0.664-0.876). The cutoff value for the GNRI was 83.4 (sensitivity, 85.2%; specificity, 62.5%). CONCLUSION: These findings suggest that the GNRI score at admission predicts high ADL at discharge in older patients with heart failure who underwent CR.

Solar-driven upgrading of biomass by coupled hydrogenation using in situ (photo)electrochemically generated H2.

With the increasing pressure to decarbonize our society, green hydrogen has been identified as a key element in a future fossil fuel-free energy infrastructure. Solar water splitting through photoelectrochemical approaches is an elegant way to produce green hydrogen, but for low-value products like hydrogen, photoelectrochemical production pathways are difficult to be made economically competitive. A possible solution is to co-produce value-added chemicals. Here, we propose and demonstrate the in situ use of (photo)electrochemically generated H2 for the homogeneous hydrogenation of itaconic acid-a biomass-derived feedstock-to methyl succinic acid. Coupling these two processes offers major advantages in terms of stability and reaction flexibility compared to direct electrochemical hydrogenation, while minimizing the overpotential. An overall conversion of up to ~60% of the produced hydrogen is demonstrated for our coupled process, and a techno-economic assessment of our proposed device further reveals the benefit of coupling solar hydrogen production to a chemical transformation.

Importance of Skeletal Muscle and Interdisciplinary Team Approach in Managing Pneumonia in Older People.

Pneumonia is the most frequent lower respiratory tract disease and a major cause of morbidity and mortality globally [...].

Quantitative Description of Bubble Formation in Response to Electrolyte Engineering.

The green hydrogen economy is expected to play a crucial role in carbon neutrality, but industrial-scale water electrolysis requires improvements in efficiency, operation costs, and capital costs before broad deployment. Electrolysis operates at a high current density and involves the substantial formation of gaseous products from the electrode surfaces to the electrolyte, which may lead to additional resistance and a resulting loss of efficiency. A detailed clarification of the bubble departure phenomena against the electrode surface and the surrounding electrolytes is needed to further control bubbles in a water electrolyzer. This study clarifies how electrolyte properties affect the measured bubble detachment sizes from the comparisons with analytical expressions and dynamic simulations. Bubble behavior in various electrolyte solutions and operating conditions was described using various physical parameters. A quantitative relationship was then established to connect electrolyte properties and bubble departure diameters, which can help regulate the bubble management through electrolyte engineering.

Synthesis of Metal Chalcogenide Semiconductors by Thermal Decomposition of Organosulfur and Organoselenium Compounds.

Metal chalcogenides - because of their excellent optical and electrical properties - are important semiconductor materials for optical devices, such as solar cells, sensors, and photocatalysts. The challenges associated with metal chalcogenides are the complexity of the conventional synthesis methods and the stringent synthesis conditions. In this study, the synthesis conditions were simplified in a solvent-free synthesis method using cadmium precursor, thiourea and selenium to synthesize metal chalcogenides, such as CdS and CdSe, which have particularly suitable band gaps for the optical devices. CdSx Se1-x solid solution was successfully synthesized under molten thiourea as the reactive reaction medium at relatively low temperatures, even at 180 °C, with residual melamine derivatives in the solid phase. The luminescence properties of CdSx Se1-x and the products in the gas and solid phases were investigated. Optimization of the synthesis conditions for solid solutions of CdSx Se1-x and the role of organic compounds in the formation of metal chalcogenides are discussed.

Photocatalytic hydrogenation of acetophenone on a titanium dioxide cellulose film.

A previously developed sustainable immobilization concept for photocatalysts based on cellulose as a renewable support material was applied for the photocatalytic hydrogenation of acetophenone (ACP) to 1-phenyl ethanol (PE). Four different TiO2 modifications (P25, P90, PC105, and PC500) were screened for the reaction showing good performance for PC25 and PC500. PC500 was selected for a detailed kinetic study to find the optimal operating conditions, and to obtain a better understanding of the photocatalytic pathway in relation to conventional and transfer hydrogenation. The kinetic data were analyzed using the pseudo-first-order reaction rate law. A complete conversion was obtained for ACP concentrations below 1 mM using a 360 nm filter and argon as the purge gas within 2-3 hours. High oxygen concentrations slow down or prevent the reaction, and wavelengths below 300 nm lead to side-products. By investigating the temperature dependency, an activation energy of 22 kJ mol-1 was determined which is lower than the activation energies for conventional and transfer hydrogenation, because the light activation of the photocatalyst turns the endothermic to an exothermic reaction. PC500 was immobilized onto the cellulose film showing a 37% lower activity that remains almost constant after multiple use.

A Permselective CeOx Coating To Improve the Stability of Oxygen Evolution Electrocatalysts.

Highly active NiFeOx electrocatalysts for the oxygen evolution reaction (OER) suffer gradual deactivation with time owing to the loss of Fe species from the active sites into solution during catalysis. The anodic deposition of a CeOx layer prevents the loss of such Fe species from the OER catalysts, achieving a highly stable performance. The CeOx layer does not affect the OER activity of the catalyst underneath but exhibits unique permselectivity, allowing the permeation of OH- and O2 through while preventing the diffusion of redox ions through the layer to function as a selective O2 -evolving electrode. The use of such a permselective protective layer provides a new strategy for improving the durability of electrocatalysts.