Bergmannkjeldsen7326

Recent years have witnessed various in-depth research efforts on self-reconstruction behavior toward electrocatalysis. Tracking the phase transformation and evolution of true active sites is of great significance for the development of self-reconstructed electrocatalysts. Here, the optimized atomic sulfur-doped bismuth nanobelt (S-Bi) is fabricated via an electrochemical self-reconstruction evolved from Bi2S3. Advanced technologies have demonstrated that the nonmetallic S atoms have been doped into the lattice Bi frame, leading to the reconstruction of local electronic structure of Bi. The as-prepared S-Bi nanobelt exhibits a remarkable NH3 generation rate of 10.28 μg h-1 mg-1 and Faradaic efficiency of 10.48%. SCH58261 Density functional theory calculations prove that the S doping can significantly lower the energy barrier of the rate-determining step and enlarge the N≡N bond for further dissociation toward N2 fixation. This work not only establishes insights into the evolution process of electrochemically derived self-reconstruction but also unravels the root of the N2 reduction reaction mechanism associated with the atomic nonmetal dopants.One approach for desalinating brackish water is to use electrode materials that electrochemically remove salt ions from water. Recent studies found that sodium-intercalating electrode materials (i.e., materials that reversibly insert Na+ ions into their structures) have higher specific salt storage capacities (mgsalt/gmaterial) than carbon-based electrode materials over smaller or similar voltage windows. These observations have led to the hypothesis that energy demands of electrochemical desalination systems can be decreased by replacing carbon-based electrodes with intercalating electrodes. To test this hypothesis and directly compare intercalation materials, we examined nine electrode materials thought to be capable of sodium intercalation in an electrochemical flow cell with respect to volumetric energy demands (W·h·L-1) and thermodynamic efficiencies as a function of productivity (i.e., the rate of water desalination, L·m-2·h-1). We also examined how the materials' charge-storage capacities changed over 50 cycles. Intercalation materials desalinated brackish water more efficiently than carbon-based electrodes when we assumed that no energy recovery occurred (i.e., no energy was recovered when the cell produced electrical power during cycling) and exhibited similar efficiencies when we assumed complete energy recovery. Nickel hexacyanoferrate exhibited the lowest energy demand among all of the materials and exhibited the highest stability over 50 cycles.There is accumulating evidence that Balkan endemic nephropathy (BEN) is an environmental disease caused by aristolochic acids (AAs) released from the decomposition of Aristolochia clematitis L., an AA-containing weed that grows abundantly in the Balkan Peninsula. AA exposure has also been associated with carcinoma development in the upper urinary tract of some patients suffering from BEN. It is believed that an aristolactam-nitrenium ion intermediate with a delocalized positive charge produced in the hepatic metabolism of AAs binds to DNA and the resulting DNA adduct is responsible for initiating the carcinoma development process. In this study, we demonstrated for the first time that the aristolactam-nitrenium ion intermediate will also react with endogenous aminothiols, for example, cysteine, N-acetylcysteine, and glutathione in vitro, and in rats, producing phase II-conjugated metabolites in a dosage-dependent manner. It is highly possible that this conjugation process consumes and ultimately deactivates this carcinogenic intermediate and acts as an important, but previously unreported, detoxification mechanism of AAs. Results also showed AAs, phase I metabolites, and the aminothiol-conjugated metabolites are rapidly eliminated from AA-exposed rats. Furthermore, we found evidence that AA exposure induced oxidative stress in rats, as indicated by the glutathione depletion in rat serum samples.Salen and salphens are important ligands in coordination chemistry due to their ability to form various metal complexes that can be used for a variety of organic transformations. However, salen/salphen complexes are difficult to separate from the reaction mixture, thereby limiting their application to homogeneous systems. Accordingly, considerable effort has been spent to heterogenize the metallosalen/salphen complexes; however, this has resulted in compromised activities and selectivities. Direct heterogenization of metallosalens to form porous organic polymers (POPs) shows promise for heterogeneous catalysis, because it would allow easy separation while retaining catalytic function. Thus, a facile synthetic strategy for preparing metallosalen/salphen-based porous organic polymers through direct molecular knitting using a Friedel-Crafts reaction is presented herein for the first time. As representative candidates, salphenM(III)Cl (M = Al3+ and Cr3+) complexes are knitted by covalent cross-linking using this facile, scalable, one-pot method to synthesize highly POPs in high yields. When incorporated with [Co(CO)4]- anions, the resulting heterogeneous Lewis acidic metal (Al3+ and Cr3+) POPs exhibit propylene oxide ring-expansion carbonylation activity on par with those of their homogeneous counterparts.Unveiling the mystery of the contribution of nonsurface or noninterface sites in a catalyst to its catalytic performance remains a great challenge because of the difficulty in capturing precisely structural information (surface plus inner) encoded in the catalyst. This work attempts to elucidate the critical role of the internal vacancy in an atomically precise 24-atom gold cluster in regulating the catalytic performance on the hydrogenation reaction of CO2. The experiment results show that the Au24 cluster with internal vacancy can mitigate sintering and exhibit high catalytic activity under relatively harsh reaction conditions, in contrast to the structurally similar Au25 cluster without internal vacancy. Our computational study suggests that the internal vacancy in Au24 provides the cluster with much more structural flexibility, which may be crucial to resisting the aggregation of the cluster and further postponing the deactivation. The hydrogenation and coupling stages of the reaction intermediates are proposed to explain the potential reaction pathway of CO2 with H2 on the Au24 catalyst with internal vacancy.