Search

The nitrate electroreduction reaction (NO3RR) offers an eco‐friendly alternative to the Haber–Bosch technology for ammonia (NH3) synthesis. However, the complex reaction process and diverse products make efficient NH3 synthesis challenging. Therefore, the rational design and preparation of highly efficient electrocatalysts are crucial for NO3RR. Herein, ultrathin copper‐nickel oxide (Cu‐NiO) nanosheets (Cu‐NiO UTNSs) are synthesized via the cyanogel‐NaBH4 hydrolysis‐reduction method, which are applied for the cathodic NO3 RR to NH3‐assisted with the anodic sulfur ion (S2−) oxidation reaction (SOR) in an electrolyzer. The ultrathin nanosheet structure, the interaction between NiO and Cu, and the formation of oxygen vacancy contribute to generating the rich active sites, regulating the electronic structure, and improving the substance adsorption. Thus, the Cu‐NiO UTNSs exhibit excellent electrocatalytic performance for NO3RR and SOR. As a bifunctional Cu‐NiO UTNSs||Cu‐NiO UTNSs electrolyzer, it can reach 10 mA cm−1 at only 0.1 V for NO3−‐to‐NH3 conversion at the cathode and S2−‐to‐S8 conversion at the anode. This work provides a promising approach for producing value‐added chemicals at a low electrolysis voltage and a strategy for pollutant treatment. [ABSTRACT FROM AUTHOR]

The ocean serves as a significant contributor of atmospheric Hydrogen (H2) with indirect greenhouse effects. However, uncertainties persist regarding internal production and consumption processes of marine H2, as well as controlling factors. Our study examined the spatial distribution and source‐sink dynamics of marine H2 in the Eastern Indian Ocean. H2 concentrations in surface seawater exhibited a range of 2.95–21.96 nmol L−1. High concentrations of H2 were observed in the anoxic water in the Bay of Bengal. Rates of H2 photo‐production and microbial consumption in surface seawater ranged from 1.80 to 17.78 nmol L−1 h−1 and 1.02–9.18 nmol L−1 h−1, respectively. When considering the entire mixed layer, photo‐production contribute to approximately 31%–43% of the total H2 removal, with cyanobacteria potentially serving as another source in the mixed layer. Compared with the sea‐to‐air exchange, microbial consumption was the primary removal pathway of H2 in seawater. Plain Language Summary: Atmospheric hydrogen (H2) can influence the environment and climate by consuming hydroxyl radicals (OH·) and indirectly raising greenhouse gas concentrations. Although the ocean serves as a significant source of atmospheric H2, the biogeochemical processes governing its presence in seawater remain poorly understood. The Eastern Indian Ocean, characterized by a substantial inflow of freshwater, exerts a distinct impact on the local ecosystem. We conducted a field investigation in the Eastern Indian Ocean to clarify the sources, sinks, and controlling factors of H2, including the Bay of Bengal with relatively higher primary productivity and the Eastern Equatorial Indian Ocean with low primary productivity, respectively. Our study involved the quantitative assessment of H2 photo‐production, microbial consumption, and sea‐to‐air exchange in seawater, along with the calculation of the H2 budget in the mixed layer. This investigation enhances our understanding of H2 cycling processes in seawater and contributes to the assessment of H2 emissions from the ocean and their impact on the atmospheric budget. Key Points: The distribution of H2 was significantly affected by river input in the Eastern Indian OceanPhoto‐production was an important source of H2 in the mixed layerMicrobial consumption was the primary sink for H2 in the mixed layer [ABSTRACT FROM AUTHOR]

Nitrite (NO2−) and hydrazine (N2H4) are common N‐pollutants in groundwater. The electrochemical method can realize the treatment of N‐pollutants and the synthesis of energy substance ammonia (NH3). Designing and synthesizing efficient electrocatalysts is of great significance. Herein, ultrathin Co0.5NiS nanosheets attached on nickel foam (Co0.5NiS‐NSs/NF) are synthesized via cyanogel‐NaBH4 hydrolysis process and succedent sulfurization approach. Owing to the ultrathin nanosheet structure and the interaction between Ni and Co, Co0.5NiS‐NSs/NF exhibits high activity for NO2− reduction reaction (NO2−RR), in which the Faraday efficiency is 92.2% and the NH3 yield is 0.25 mmol h−1 cm−2 at −0.15 V potential. Meanwhile, Co0.5NiS‐NSs/NF also displays remarkable activity for N2H4 oxidation reaction in KOH electrolyte. Therefore, a symmetrical Co0.5NiS‐NSs/NF||Co0.5NiS‐NSs/NF electrolyzer is assembled, which only needs the operating voltage of 0.36 V to reach 10 mA cm−2 for NO2−‐to‐NH3 conversion in the presence of N2H4. This work reports a promising and efficient strategy for NH3 production at a small operating voltage and treatment of the N‐pollutants. [ABSTRACT FROM AUTHOR]

BACKGROUND: Pyraclostrobin manifests a bright promise in agriculture with the characteristics of a broad spectrum, high efficiency, low toxicity, non‐target biosafety, and friendliness to users and the environment due to its ability to inhibit mitochondrial respiration in a novel mode of action. 1‐(4‐chlorophenyl)‐3‐pyrazolol is an essential intermediate for the preparation of pyraclostrobin. The commercial technology for the production of 1‐(4‐chlorophenyl)‐3‐pyrazolol by oxidizing 1‐(4‐chlorophenyl)pyrazolidan‐3‐one with H2O2 in strong an alkali solution is risky and not friendly to the environment. RESULTS: A solid Fe/AC catalyst is constructed by loading ferric on commercial activated carbon. The activated carbon and ferric act cooperatively to upgrade the oxidation rate of 1‐(4‐chlorophenyl)pyrazolidan‐3‐one and the yield of 1‐(4‐chlorophenyl)‐3‐pyrazolol with air. The best catalyst is Fe/AC supported with 15% Fe2O3 on activated carbon of 100 ~ 120 mesh without activation. CONCLUSION: The Fe/AC catalyst is able to not only accelerate the oxidation of 1‐(4‐chlorophenyl) pyrazolidin‐3‐one but also obtain a higher yield of 1‐(4‐chlorophenyl)‐3‐pyrazolol than FeCl3 or activated carbon can in 5%(wt.) NaOH solution. The highest 1‐(4‐chlorophenyl)‐3‐pyrazolol yield is obtained by a gas stream containing 60%(wt.) oxygen with a Fe/AC dosage of 1.25 g L−1. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

High storage capacity, high separation selectivity, and high structure stability are essential for an idea gas adsorbent. However, it is not easy to achieve all three at the same time, even for the promising metal-organic framework (MOF) adsorbents. We demonstrate herein that robust [Sc 3 O]-organic frameworks could be regulated by a micropore combination strategy for high-performance acetylene adsorption. Under the same solvent system with formic acid as a modulator, similar tritopic ligands extend [Sc 3 O(COO) 6 ] trigonal-prismatic clusters to generate SNNU-5-Sc and SNNU-150-Sc adsorbents. Notably, the two Sc-MOFs can keep their architectures over 24 h in water at different pH values (2-12) or at 90 °C. Modulated by the linker symmetry, the final stacking metal-organic polyhedral cages produce open window sizes of about 10 Å for SNNU-5-Sc and 5 Å + 7 Å for SNNU-150-Sc. Due to such micropore combinations, SNNU-5-Sc exhibits a top-level C 2 H 2 uptake of 211.2 cm 3 g -1 (1 atm and 273 K) and SNNU-150-Sc shows high C 2 H 2 /CH 4 , C 2 H 2 /C 2 H 4 , and C 2 H 2 /CO 2 selectivities of 80.65, 4.03, and 8.19, respectively, under ambient conditions. Dynamic breakthrough curves obtained on a fixed-bed column and grand canonical Monte Carlo (GCMC) simulations further support their prominent acetylene storage and purification performance. High framework stability, storage capacity, and separation selectivity make SNNU-5-Sc and SNNU-150-Sc ideal acetylene adsorbents in practical applications.