N2 electroreduction into NH3 represents an attractive prospect for N2 utilization. Nevertheless, this process suffers from low Faraday efficiency (FE) and yield rate for NH3. In this work, a highly efficient metal‐free catalyst is developed by introducing F atoms into a 3D porous carbon framework (F‐doped carbon) toward N2 electroreduction. At −0.2 V versus reversible hydrogen electrode (RHE), the F‐doped carbon achieves the highest FE of 54.8% for NH3, which is 3.0 times as high as that (18.3%) of pristine carbon frameworks. Notably, at −0.3 V versus RHE, the yield rate of F‐doped carbon for NH3 reaches 197.7 µgNH3 mg−1cat. h−1. Such a value is more than one order of magnitude higher than those of other metal‐free electrocatalysts under the near‐ambient conditions for NH3 product to date. Mechanistic studies reveal that the improved performance in N2 electroreduction for F‐doped carbon originates from the enhanced binding strength of N2 and the facilitated dissociation of N2 into *N2H. F bonding to C atom creates a Lewis acid site due to the different electronegativity between the F and C atoms. As such, the repulsive interaction between the Lewis acid site and proton H suppresses the activity of H2 evolution reaction, thus enhancing the selectivity of N2 electroreduction into NH3.

The electrooxidation of propylene into propylene oxide under ambient conditions represents an attractive approach toward propylene oxide. However, this process suffers from a low yield rate over reported electrocatalysts. In this work, we develop an efficient electrocatalyst of Ag3PO4 for the electrooxidation of propylene into propylene oxide. The Ag3PO4 cubes with (100) facets exhibit the highest yield rate of 5.3 gPO m−2 h−1 at 2.4 V versus reversible hydrogen electrode, which is 1.6 and 2.5 times higher than those over Ag3PO4 rhombic dodecahedra with (110) facets and tetrahedra with (111) facets, respectively. The theoretical calculations reveal that the largest polarization of propylene on Ag3PO4 (100) facets is beneficial to break the symmetric π bonding and facilitate the formation of C-O bond. Meanwhile, Ag3PO4(100) facets exhibit the lowest adsorption energies of *C3H6 and *OH, inducing the lowest energy barrier of the rate-determining step and thus accounting for the highest catalytic performance.

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Tara gum/silver composite superabsorbent polymers were synthesized with tara gum grafted poly(acrylic acid), using K 2 S 2 O 8 (KPS) as an initiator and N,N -methylenebisacrylamide (MBA) as a cross-linker. The products were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The results showed that the silver ions were partially reduced to Ag 0 and the amorphous nanoparticles containing Ag 0 and Ag 2 O were around 10~50 nm in size The tara gum/silver composite superabsorbent polymers exhibited an interconnected porous structure with strong water absorption capacity. The swelling ratio of each product could reach 473 g/g in distilled water and 62 g/g in 0.9% NaCl solution. The antimicrobial activity of the samples against Staphylococcus aureus and Escherichia coli increased with the addition of AgNO 3 from 0 to 125 mg. This work indicates that the developed tara gum/silver composite superabsorbent polymers can be potentially used for biomedical applications.

For the electrooxidation of propylene into 1,2-propylene glycol (PG), the process involves two key steps of the generation of *OH and the transfer of *OH to the CC bond in propylene. The strong *OH binding energy (E B(*OH)) favors the dissociation of H2O into *OH, whereas the transfer of *OH to propylene will be impeded. The scaling relationship of the E B(*OH) plays a key role in affecting the catalytic performance toward propylene electrooxidation. Herein, we adopt an immobilized Ag pyrazole molecular catalyst (denoted as AgPz) as the electrocatalyst. The pyrrolic N–H in AgPz could undergo deprotonation to form pyrrolic N (denoted as AgPz-Hvac), which can be protonated reversibly. During propylene electrooxidation, the strong E B(*OH) on AgPz favors the dissociation of H2O into *OH. Subsequently, the AgPz transforms into AgPz-Hvac that possesses weak E B(*OH), benefiting to the further combination of *OH and propylene. The dynamically reversible interconversion between AgPz and AgPz-Hvac accompanied by changeable E B(*OH) breaks the scaling relationship, thus greatly lowering the reaction barrier. At 2.0 V versus Ag/AgCl electrode, AgPz achieves a remarkable yield rate of 288.9 mmolPG gcat –1 h–1, which is more than one order of magnitude higher than the highest value ever reported.

Cu-based tandem catalysts have widely been exploited to improve the catalytic performance for multi-carbon (C2+) products towards CO2 electroreduction. Nevertheless, the underlying reaction mechanism for tandem catalytic system remains ambiguity. Herein, we unraveled the relationship between the behavior of adsorbed CO intermediate (*CO) and the process of C-C coupling. Due to the low coverage of *CO, the process of C-C coupling has always been restricted for Cu catalysts. Through regulating the molar ratios of CO2 to CO in co-feeding gases, we found that the moderate surface coverage of *CO was beneficial for the electroreduction of CO2 into ethylene (C2H4). Meanwhile, the cross-coupling process between CO2 and CO was proved to be responsible for the enhanced activity of C2H4 according to isotopic labeling experiments. We constructed a tandem model with cobalt phthalocyanine (CoPc) as CO-generating component on Cu to further verify the tandem mechanism. With the introduction of CoPc onto the surface of Cu, the partial current density for C2H4 reached as high as 313 mA cm-2 at applied current density of 480 mA cm-2, which was one-fold higher than that (165 mA cm-2) of Cu film. In-situ Raman measurements further revealed that CO generated by CoPc increased the coverage of *CO on the surface of Cu, facilitating the process of C-C coupling.