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Maleic acid (MA) production from furfural (FF) is a promising electrochemical oxidation reaction to convert biomass into valuable platform chemicals. However, a library of oxidation activities needs to be studied more. Herein, we demonstrate that Bi doping in lead oxide is effective in tuning the activity for complicated FF oxidation reactions. Bi-doped lead oxide (PbBiOx) can selectively produce MA from the electrochemical FF oxidation reaction (FFOR), leading to a maximum MA yield of 57% with an optimal Bi content of Pb0.9Bi0.1Ox. Its selectivity, the relative yield of MA in relation to 5-hydroxy-2(5H)-dihydrofuran-2-one (HFN), is largely enhanced by 17 times, compared to pristine PbOx. We propose that Bi affects the oxidation state of Pb and thus the selectivity of the oxidation reaction, which is supported by a series of product analyses of the electrochemical oxidation of FF (reactant), HFN (intermediate), and maleic acid (product). While PbOx prepared by a simple thermal decomposition method is composed of a PbO2 and Pb3O4 mixture, the ratio of PbO2 to Pb3O4 decreases in PbBiOx, suppressing active Pb4+ under the applied potentials. PbBiOx exhibited a lower conversion rate of FF as well as greater preservation of the carbon source during the FFOR than PbOx, and Bi-doping was also shown to be effective in retarding the overoxidation of MA to CO2. Our study shows that mixed metal oxides can be effective in adjusting the oxidation activity and contribute to selective electrosynthesis from multi-step biomass conversion. [ABSTRACT FROM AUTHOR]

Direct partial oxidation of methane to liquid oxygenates has been regarded as a potential route to valorize methane. However, CH4 activation usually requires a high temperature and pressure, which lowers the feasibility of the reaction. Here, we propose an electro-assisted approach for the partial oxidation of methane, using in-situ cathodically generated reactive oxygen species, at ambient temperature and pressure. Upon using acid-treated carbon as the electrocatalyst, the electro-assisted system enables the partial oxidation of methane in an acidic electrolyte to produce oxygenated liquid products. We also demonstrate a high production rate of oxygenates (18.9 μmol h−1) with selective HCOOH production. Mechanistic analysis reveals that reactive oxygen species such as ∙OH and ∙OOH radicals are produced and activate CH4 and CH3OH. In addition, unstable CH3OOH generated from methane partial oxidation can be additionally reduced to CH3OH on the cathode, and so-produced CH3OH is further oxidized to HCOOH, allowing selective methane partial oxidation. This study presents the electrochemically assisted partial oxidation of methane to produce liquid oxygenate, HCOOH, selectively which involves in-situ cathodically generated reactive oxygen species with an acid-treated carbon electrocatalyst. [ABSTRACT FROM AUTHOR]

To design active and selective catalysts for deriving value-added C2+ chemicals from the electrochemical CO2 reduction reaction (CO2RR), comprehensive studies on the catalyst system are necessary. However, the substrate-induced properties and their effects have been overlooked despite the importance of extrinsic properties in the CO2RR. In this study, we investigated the substrate effects on CO2RR performance by applying well-defined Cu2O nanocube catalysts to two representative substrates, porous carbon paper, and glassy carbon substrate. Although the same Cu2O catalyst was applied to both substrates, the product selectivity and total current density varied significantly depending on the type of substrate, especially for the CO Faradaic efficiency (FE). Computational fluid dynamics (CFD) simulation and gas diffusion control experiments revealed that a substrate with porous media (i.e., carbon paper) can provide an unnoticed gas diffusion pathway of reactant CO2 and the intermediate product, CO. This substrate facilitated CO2 supply to the catalyst layer while letting CO diffuse back from the catalyst layer to the porous media of the substrate, contributing to the high FECO on porous carbon paper. Based on these findings, we rationally developed a double-layered tandem catalyst by employing a different gas diffusion rate and direction, and achieved an exceptionally high FEC2+ of 62.1% on a carbon paper/Cu/Ag-configured catalyst. This study elucidates that the substrate should be carefully considered for designing an efficient CO2RR system and to avoid the misinterpretation of results. Therefore, gas diffusion, which is the most important extrinsic property relevant to the CO2RR, is practically influenced by the substrate properties. [ABSTRACT FROM AUTHOR]

A zero-gap membrane-electrode assembly (MEA) electrolyzer is a promising design for electrochemical CO2 reduction reactions (eCO2RRs), where gaseous CO2 is directly fed without catholyte. The zero-gap junction between the catalyst and the membrane can have distinct chemical environments and mass transfer properties from the conventional H-type cell but is rarely studied. In this work, we designed an integrated experimental-simulation study in MEA to understand the zero-gap junction and factors to determine the eCO2RR activity to multi-carbon production. We developed a simple synchronous ionomer/catalyst activation step under alkaline conditions to form jagged CuO nanoparticles whose unique morphological evolution facilitates the C2+ chemical production for the zero-gap MEA electrolyzer. Moreover, under gas-fed and high–current density conditions, computational fluid dynamics suggests that the mass transfer limitation of water as a proton source across the catalyst-membrane layer and cathode kinetic overpotential are critical to determining C2+ chemical production in the range of several micrometers. From the chemical-physical understanding, we achieved a high partial current density of 336.5 mA cm−2 and a faradaic efficiency of 67.3% towards C2+ chemicals. [ABSTRACT FROM AUTHOR]

Recent accumulating epidemiological evidence underlines the important role of environmental exposures on kidney diseases. Among environmental exposures, this study addresses "Green space," which has been recognized as one of the major environmental exposures at the population level. We review a total of seven epidemiological studies currently published on greenness and kidney disease. We also discuss knowledge gaps in the epidemiological evidence in relation to study design, greenness exposure index, emerging kidney outcomes, and inequalities. With an increase in public attention regarding environmental risks and climate change, an improved understanding of the beneficial effects of green space can play an important role in promoting kidney health.

Unraveling the atomistic synergistic effects of nanoalloys on the electrocatalytic CO 2 reduction reaction (eCO 2 RR), especially in the presence of copper, is of paramount importance. However, this endeavor encounters significant challenges due to the lack of the crystallographically determined atomic-level structure of appropriate monometallic and bimetallic analogues. Herein, we report a one-pot synthesis and structure characterization of a AuCu nanoalloy cluster catalyst, [Au 15 Cu 4 (DPPM) 6 Cl 4 (C≡CR) 1 ] 2+ (denoted as Au 15 Cu 4 ). Single-crystal X-ray diffraction analysis reveals that Au 15 Cu 4 comprises two interpenetrating incomplete, centered icosahedra (Au 9 Cu 2 and Au 8 Cu 3 ) and is protected by six DPPM, four halide, and one alkynyl ligand. The Au 15 Cu 4 cluster and its closest monometal structural analogue, [Au 18 (DPPM) 6 Br 4 ] 2+ (denoted as Au 18 ), as model systems, enable the elucidation of the atomistic synergistic effects of Au and Cu on eCO 2 RR. The results reveal that Au 15 Cu 4 is an excellent eCO 2 RR catalyst in a gas diffusion electrode-based membrane electrode assembly (MEA) cell, exhibiting a high CO Faradaic efficiency (FE CO ) of >90%, and this efficiency is substantially higher than that of the undoped Au 18 (FE CO : 60% at -3.75 V). Au 15 Cu 4 exhibits an industrial-level CO partial current density of up to -413 mA/cm 2 at -3.75 V with the gas CO 2 -fed MEA, which is 2-fold higher than that of Au 18 . The density functional theory (DFT) calculations demonstrate that the synergistic effects are induced by Cu doping, where the exposed pair of AuCu dual sites was suggested for launching the eCO 2 RR process. Besides, DFT simulations reveal that these special dual sites synergistically coordinate a moderate shift in the d-state, thus enhancing its overall catalytic performance.

Tibolone, a selective tissue estrogenic activity regulator, is a synthetic steroid with distinct pharmacological and clinical characteristics in contrast to conventional menopausal hormone therapy. Tibolone induces estrogenic activity in the brain, vagina, and bone but remains inactive in the endometrium and breast. In particular, several studies have investigated whether tibolone usage increases the risk of breast cancer. This study aims to determine the effects of tibolone on the breast by focusing on the relation between tibolone use and breast cancer. Our investigation emphasizes recent studies, particularly those based on Asian populations., Competing Interests: No potential conflict of interest relevant to this article was reported., (Copyright © by The Korean Society of Menopause.)

Cations in an electrolyte modulate microenvironments near the catalyst surface and affect product distribution from an electrochemical CO 2 reduction reaction, and thus, their interaction with intermediate states has been tried to be probed. Herein, we directly observed the cation effect on *CO intermediates on the Cu(OH) 2 -derived catalyst in real time through operando surface-enhanced Raman spectroscopy at high overpotentials (-1.0 V RHE ). Atop *CO peaks are composed of low-frequency binding *CO (*CO LFB ) and high-frequency binding *CO (*CO HFB ) because of their adsorption sites. These two *CO intermediates are found to have different sensitivities to the cation-induced field, and each *CO is proposed to be suitably stabilized for efficient C-C coupling. The proportions between *CO HFB and *CO LFB are dependent on the type of alkali cations, and the increases in the *CO HFB ratio have a high correlation with selective C 2 H 4 production under K + and Cs + , indicating that *CO HFB is the dominant and fast active species. In addition, as the hydrated cation size decreases, *CO LFB is more sensitively red-shifted than *CO HFB , which promotes C-C coupling and suppresses C 1 products. Through time-resolved operando measurements, dynamic changes between the two *CO species are observed, showing the rapid initial adsorption of *CO HFB and subsequently reaching a steady ratio between *CO LFB and *CO HFB .