The electrocatalytic C–N coupling for one-step urea synthesis under ambient conditions serves as the promising alternative to the traditional urea synthetic protocol. However, the hydrogenation of intermediate species hinders the efficient urea synthesis. Herein, the oxygen vacancy-enriched CeO2 was demonstrated as the efficient electrocatalyst with the stabilization of the crucial intermediate of *NO via inserting into vacant sites, which is conducive to the subsequent C–N coupling process rather than protonation, whereas the poor selectivity of C–N coupling with protonation was observed on the vacancy-deficient catalyst. The oxygen vacancy-mediated selective C–N coupling was distinguished and validated by the in situ sum frequency generation spectroscopy. The introduction of oxygen vacancies tailors the common catalyst carrier into an efficient electrocatalyst with a high urea yield rate of 943.6 mg h–1 g–1, superior than that of partial noble-metal-based electrocatalysts. This work provides novel insights into the catalyst design and developments of coupling systems.

Electrocatalytic urea synthesis emerged as the promising alternative of Haber–Bosch process and industrial urea synthetic protocol. Here, we report that a diatomic catalyst with bonded Fe–Ni pairs can significantly improve the efficiency of electrochemical urea synthesis. Compared with isolated diatomic and single-atom catalysts, the bonded Fe–Ni pairs act as the efficient sites for coordinated adsorption and activation of multiple reactants, enhancing the crucial C–N coupling thermodynamically and kinetically. The performance for urea synthesis up to an order of magnitude higher than those of single-atom and isolated diatomic electrocatalysts, a high urea yield rate of 20.2 mmol h−1 g−1 with corresponding Faradaic efficiency of 17.8% has been successfully achieved. A total Faradaic efficiency of about 100% for the formation of value-added urea, CO, and NH3 was realized. This work presents an insight into synergistic catalysis towards sustainable urea synthesis via identifying and tailoring the atomic site configurations.

Electrocatalytic oxidation of 5‐hydroxymethylfurfural (HMF) provides an efficient way to obtain high‐value‐added biomass‐derived chemicals. Compared with other transition metal oxides, CuO exhibits poor oxygen evolution reaction performance, leading to high Faraday efficiency for HMF oxidation. However, the weak adsorption and activation ability of CuO to OH− species restricts its further development. Herein, the CuO–PdO heterogeneous interface is successfully constructed, resulting in an advanced onset‐potential of the HMF oxidation reaction (HMFOR), a higher current density than CuO. The results of open‐circuit potential, in situ infrared spectroscopy, and theoretical calculations indicate that the introduction of PdO enhances the adsorption capacity of the organic molecule. Meanwhile, the CuO–PdO heterogeneous interface promotes the adsorption and activation of OH− species, as demonstrated by zeta potential and electrochemical measurements. This work elucidates the adsorption enhancement mechanism of heterogeneous interfaces and provides constructive guidance for designing efficient multicomponent electrocatalysts in organic electrocatalytic reactions.

Electrocatalytic CN coupling between carbon dioxide and nitrate has emerged to meet the comprehensive demands of carbon footprint closing, valorization of waste, and sustainable manufacture of urea. However, the identification of catalytic active sites and the design of efficient electrocatalysts remain a challenge. Herein, the synthesis of urea catalyzed by copper single atoms decorated on a CeO2 support (denoted as Cu1–CeO2) is reported. The catalyst exhibits an average urea yield rate of 52.84 mmol h−1 gcat.−1 at −1.6 V versus reversible hydrogen electrode. Operando X‐ray absorption spectra demonstrate the reconstitution of copper single atoms (Cu1) to clusters (Cu4) during electrolysis. These electrochemically reconstituted Cu4 clusters are real active sites for electrocatalytic urea synthesis. Favorable CN coupling reactions and urea formation on Cu4 are validated using operando synchrotron‐radiation Fourier transform infrared spectroscopy and theoretical calculations. Dynamic and reversible transformations of clusters to single‐atom configurations occur when the applied potential is switched to an open‐circuit potential, endowing the catalyst with superior structural and electrochemical stabilities.

Integrating biomass upgrading and hydrogen production in an electrocatalytic system is attractive both environmentally and in terms of sustainability. Conventional electrolyser systems coupling anodic biosubstrate electrooxidation with hydrogen evolution reaction usually require electricity input. Herein, we describe the development of an electrocatalytic system for simultaneous biomass upgrading, hydrogen production, and electricity generation. In contrast to conventional furfural electrooxidation, the employed lowpotential furfural oxidation enabled the hydrogen atom of the aldehyde group to be released as gaseous hydrogen at the anode at a low potential of approximately 0 V RHE (vs. RHE). The integrated electrocatalytic system could generate electricity of about 2 kWh per cubic meter of hydrogen produced. This study may provide a transformative technology to convert electrocatalytic biomass upgrading and hydrogen production from a process requiring electricity input into a process to generate electricity.

With the emergence of many antibiotic-resistant strains worldwide, antimicrobial peptides (AMPs) are being evaluated as promising alternatives to conventional antibiotics. P3, a novel hemoglobin peptide derived from bovine erythrocytes, exhibited modest antimicrobial activity in vitro. We evaluated the antimicrobial activities of P3 and an analog, JH-3, both in vitro and in vivo. The MICs of P3 and JH-3 ranged from 3.125 g/ml to 50 g/ml when a wide spectrum of bacteria was tested, including multidrug-resistant strains. P3 killed bacteria within 30 min by disrupting the bacterial cytoplasmic membrane and disturbing the intracellular calcium balance. Circular dichroism (CD) spectrometry showed that P3 assumed an ␣-helical conformation in bacterial lipid membranes, which was indispensable for antimicrobial activity. Importantly, the 50% lethal dose (LD 50 ) of JH-3 was 180 mg/kg of mouse body weight after intraperitoneal (i.p.) injection, and no death was observed at any dose up to 240 mg/kg body weight following subcutaneous (s.c.) injection. Furthermore, JH-3 significantly decreased the bacterial count and rescued infected mice in a model of mouse bacteremia. In conclusion, P3 and an analog exhibited potent antimicrobial activities and relatively low toxicities in a mouse model, indicating that they may be useful for treating infections caused by drug-resistant bacteria.T he overuse of traditional antibiotics has triggered the frequent emergence of multidrug-resistant (MDR) bacteria, which pose significant threats to public health. Bacterial resistance is usually attributable to mutations and can spread, rendering the problem worse (1-3). Extensively mutated bacteria become resistant to many conventional chemotherapeutics. Since the early 1960s, many novel antibiotics have been prepared, but these are usually chemical variations of older and conventional antibiotics (4). There is an urgent need to find novel antimicrobial agents that control infections caused by MDR bacteria.Antimicrobial peptides (AMPs) have recently attracted significant attention (5). They are primitive components of innate immune systems and play multiple roles in immune defense (6, 7). AMPs are widespread in unicellular organisms, plants, and animals, and more than 1,600 have been identified in a wide range of organisms (8-10). Most natural AMPs exhibit broad-spectrum activities against bacteria (including MDR bacteria), fungi, viruses (including HIV), and tumors (11-13). Although many potent AMPs have been identified, a lack of knowledge about the mechanisms of action and high-level AMP toxicities are major obstacles on the path to clinical use (14). Therefore, the design of novel potent AMPs exhibiting low toxicities in vivo and the identification of the mechanisms of AMP-membrane interactions are important for the development of novel antimicrobial agents.Recently, we reported the first isolation of P3, a component of the bovine hemoglobin ␣-subunit (15). Its primary sequence is VNFKLLSHSLLVTLASHL (1,992.401 Da). The bovine hemoglobin P3 ...

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