Proton-exchange membrane fuel cells enable the portable utilization of hydrogen (H2) as an energy resource. Current electrolytic materials have limitation, and there is an urgent need to develop new ...materials showing especially high proton conductivity. Here, we report the ultra-fast proton conduction in a novel metal–organic framework, MFM-808, which adopts an unprecedented topology and a unique structure consisting of two-dimensional layers of {Zr6}-clusters. By replacing the bridging formate with sulfate ligands within {Zr6}-layers, the modified MFM-808-SO4 exhibits an exceptional proton conductivity of 0.21 S·cm–1 at 85 °C and 99% relative humidity. Modeling by molecular dynamics confirms that proton transfer is promoted by an efficient two-dimensional conducting network assembled by sulfate–{Zr6}-layers. MFM-808-SO4 also possesses excellent photocatalytic activity for water splitting to produce H2, paving a new pathway to achieve a renewable hydrogen-energy cycle.
Abstract
Electrochemical reduction of carbon dioxide is a clean and highly attractive strategy for the production of organic products. However, this is hindered severely by the high negative ...potential required to activate carbon dioxide. Here, we report the preparation of a copper-electrode onto which the porous metal–organic framework Cu
2
(L) H
4
L = 4,4′,4″,4′′′-(1,4-phenylenebis(pyridine-4,2,6-triyl))tetrabenzoic acid can be deposited by electro-synthesis templated by an ionic liquid. This decorated electrode shows a remarkable onset potential for reduction of carbon dioxide to formic acid at −1.45 V vs. Ag/Ag
+
, representing a low value for electro-reduction of carbon dioxide in an organic electrolyte. A current density of 65.8 mA·cm
−2
at −1.8 V vs. Ag/Ag
+
is observed with a Faradaic efficiency to formic acid of 90.5%. Electron paramagnetic resonance spectroscopy confirms that the templated electro-synthesis affords structural defects in the metal–organic framework film comprising uncoupled Cu(II) centres homogenously distributed throughout. These active sites promote catalytic performance as confirmed by computational modelling.
•Analyzes whether women in academia benefit less from their academic achievements than men (devaluation theory).•Among tenured professors, women show a 32% higher chance of becoming a professor than ...men.•Interaction effects reveal that women do not benefit less from academic achievements.•Women tend to benefit more from their scholarly publications than men.•We find no support for the devaluation of women's academic achievements.
Theories on gender bias argue that women in academia benefit less from their academic achievements than men do; women, as a result, show lower rates of success in becoming tenured professors. Based on longitudinal data from CVs of virtually all psychologists in German academia, we analyze factors that lead to a first permanent professorship in German psychology departments. We find no overall gender differences in getting a tenured position when considering all psychologists and holding research productivity and other observable factors constant. Among currently tenured professors, women show a 32% higher chance of having gotten tenure than men. Interaction effects reveal that women's publishing or signaling investments are not devalued when they try to obtain tenure. We particularly find that women benefit more from their scholarly publications than men do. Hence, we find no support for gender bias or devaluation of women's academic achievements.
In the endoplasmic reticulum (ER), secretory and transmembrane proteins fold into their native conformation and undergo posttranslational modifications important for their activity and structure. ...When protein folding in the ER is inhibited, signal transduction pathways, which increase the biosynthetic capacity and decrease the biosynthetic burden of the ER to maintain the homeostasis of this organelle, are activated. These pathways are called the unfolded protein response (UPR). In this review, we briefly summarize principles of protein folding and molecular chaperone function important for a mechanistic understanding of UPR-signaling events. We then discuss mechanisms of signal transduction employed by the UPR in mammals and our current understanding of the remodeling of cellular processes by the UPR. Finally, we summarize data that demonstrate that UPR signaling feeds into decision making in other processes previously thought to be unrelated to ER function, e.g., eukaryotic starvation responses and differentiation programs.
Six compounds based on dipicolinic acid esters have been synthesized and Hirshfeld surfaces used to investigate the structure-directing effects of functional groups in controlling their solid-state ...behavior. Compounds 1–4 are 4-bromo dipicolinic acid esters substituted with methyl, ethyl, propyl, and benzyl groups, respectively. The main structure-directing motif within 1–3 is a pairwise O···H interaction involving two carbonyl oxygen atoms and two aromatic H atoms. The introduction of bulky benzyl groups in 4 forces a significant change in the position of this interaction. Compounds 2 and 4 were used in Suzuki coupling reactions to prepare extended analogues 5 and 6, respectively, and their solid-state behavior was also studied using Hirshfeld surfaces. Extension of these dipicolinic acid esters results in the complete loss of the pairwise O···H interaction in 5, where the dominant structure-directing motifs are π-based interactions. However, the pairwise O···H interaction reappears for the more flexible 6, demonstrating control of the solid-state structure of these dipicolinic acid derivatives through the choice of functional groups.
How do moral arguments influence economic decisions? This study reconstructs five discussions about offshoring production to low-cost countries to understand how moral arguments attack the legitimacy ...of economic strategies. From these case studies about offshoring, I derive three mechanisms by which moral arguments influence economic decisions. Firstly, moral arguments appeal to values, influencing what their addressee defines as economically rational. Secondly, denouncing management decisions as immoral can deprive managers of valuable social capital and legitimacy within their company, thereby exerting economic pressure. Thirdly, depicting management decisions as immoral can destroy a company’s public legitimacy, further exerting economic pressure. Apart from highlighting the social mechanisms underlying moral influence, this article also shows the limits of influence-seeking through moral arguments. It contributes to the existing literature on legitimacy and economic decision-making, especially with regard to offshoring. The article concludes by developing insights about how moral arguments and interest-seeking interact in capitalism based on the empirical material.
Optimization of active sites and stability under irradiation are important targets for sorbent materials that might be used for iodine (I2) storage. Herein, we report the direct observation of I2 ...binding in a series of Cu(II)-based isostructural metal–organic frameworks, MFM-170, MFM-172, MFM-174, NJU-Bai20, and NJU-Bai21, incorporating various functional groups (–H, −CH3, – NH2, –CC–, and −CONH–, respectively). MFM-170 shows a reversible uptake of 3.37 g g–1 and a high packing density of 4.41 g cm–3 for physiosorbed I2. The incorporation of −NH2 and –CC– moieties in MFM-174 and NJU-Bai20, respectively, enhances the binding of I2, affording uptakes of up to 3.91 g g–1. In addition, an exceptional I2 packing density of 4.83 g cm–3 is achieved in MFM-174, comparable to that of solid iodine (4.93 g cm–3). In situ crystallographic studies show the formation of a range of supramolecular and chemical interactions I···N, I···H2N and I···CC, I–CC–I between −NH2, –CC– sites, respectively, and adsorbed I2 molecules. These observations have been confirmed via a combination of solid-state nuclear magnetic resonance, X-ray photoelectron, and Raman spectroscopies. Importantly, γ-irradiation confirmed the ultraresistance of MFM-170, MFM-174, and NJU-Bai20 suggesting their potential as efficient sorbents for cleanup of radioactive waste.
The development of materials showing rapid proton conduction with a low activation energy and stable performance over a wide temperature range is an important and challenging line of research. Here, ...we report confinement of sulfuric acid within porous MFM-300(Cr) to give MFM-300(Cr)·SO4(H3O)2, which exhibits a record-low activation energy of 0.04 eV, resulting in stable proton conductivity between 25 and 80 °C of >10–2 S cm–1. In situ synchrotron X-ray powder diffraction (SXPD), neutron powder diffraction (NPD), quasielastic neutron scattering (QENS), and molecular dynamics (MD) simulation reveal the pathways of proton transport and the molecular mechanism of proton diffusion within the pores. Confined sulfuric acid species together with adsorbed water molecules play a critical role in promoting the proton transfer through this robust network to afford a material in which proton conductivity is almost temperature-independent.
This paper uses a new age period cohort model to show that among cohorts born between 1935 and 1975, cohorts born around 1950 are significantly above the income trend in most countries. However, such ...inequalities between generations are much stronger in conservative, continental European welfare states, compared to social democratic and liberal welfare states. As we show, this is because conservative welfare states expose some cohorts to high youth unemployment and make lifetime earnings dependent on a favorable entry into the labor market. We thus demonstrate that conservative welfare states have put the burden of adjustment to the post-1975 economic slowdown on birth cohorts that could not get stable jobs before 1975, while similar cohort inequalities are much weaker in liberal and social democratic welfare states. In these latter two welfare regimes, the burden of adjustment to the post-1975 economic slowdown was not put on the shoulders of some cohorts relative to others. Our analysis is the first to show which welfare regimes are more conducive to such inequalities between cohorts and what mechanisms lead to these material cohort inequalities.
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