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A novel Ir−Mn dual‐atom electrocatalyst is synthesized by a facile ion‐exchange method by incorporating Ir in SrMnO3, which yields an extremely high activity and stability for the oxygen evolution reaction (OER). The ion exchange process occurs in a self‐limitation way, which favors the formation of Ir−Mn dual‐atom in the IrMnO9 unit. The incorporation of Ir modulates the electronic structure of both Ir and Mn, thereby resulting in a shorter distance of the Ir−Mn dual‐atom (2.41 Å) than the Mn−Mn dual‐atom (2.49 Å). The modulated Ir−Mn dual‐atom enables the same spin direction O (↑) of the adsorbed *O intermediates, thus facilitating the direct coupling of the two adsorbed *O intermediates to release O2 via the oxygen‐oxygen radical coupling mechanism. Electrochemical tests reveal that the Ir‐SrMnO3 exhibits a superior OER's activity with a low overpotential of 207 mV at 10 mA cm−2 and achieves a mass specific activity of 1100 A gIr−1 at 1.5 V. The proton‐exchange‐membrane water electrolyzer with the Ir‐SrMnO3 catalyst exhibits a low electrolysis voltage of 1.63 V at 1.0 A cm−2 and a stable 2000‐h operation with a decay of only 15 μV h−1 at 0.5 A cm−2. [ABSTRACT FROM AUTHOR]

NiFe-based oxyhydroxides are promising electrocatalysts for the oxygen evolution reaction (OER) in alkaline media, but further enhancing their OER performance remains a significant challenge. Herein, we in situ incorporated polyoxometalates into NiFe oxyhydroxides to form a homogeneous/heterogeneous hybrid material, which induces the electronic interaction between Ni, Fe and Mo sites, as revealed by a variety of characterization experiments and theoretical calculations. The resulting hybrid electrocatalyst delivers a low overpotential of 203 mV at 10 mA cm−2 and a TOF of 2.34 s−1 at 1.53 V in alkaline media. This work presents a critical step towards developing high-performance OER catalysts by constructing metal–POM hybrids. [ABSTRACT FROM AUTHOR]

It is challenging to develop highly active and durable electrocatalysts for hydrogen evolution reaction (HER) in alkaline water electrolysis. Herein, an electrocatalyst is synthesized with highly dispersed cerium in a nickel matrix, showing an overpotential of 169 mV for HER at a current density of 500 mA cm−2, about 137 mV lower than that observed without cerium. Kinetic analysis results suggest that doping cerium facilitates the evolution of intermediate H for HER, thus accelerating the process of water dissociation. Density functional theory (DFT) calculations also indicate that the introduction of highly dispersed cerium can lower the energy barrier of the kinetically sluggish Volmer step by altering the orbital occupation near the Fermi level, promoting the process of water dissociation. Furthermore, the electrolyzer constructed with the electrocatalyst exhibits a cell voltage as low as 1.67 V at 800 mA cm−2 for 2000 h in 7 м KOH at 80 °C. The robust property makes it an excellent candidate electrocatalyst for practical applications. [ABSTRACT FROM AUTHOR]

Identifying electrocatalysts with functions of easy dissociation of water, rapid transformation of hydroxyl and facile hydrogen‐hydrogen bond formation are indispensable while challenge for realizing efficient alkaline hydrogen evolution reaction (HER). Herein, we presented the design of Ni3Sn2‐NiSnOx nanocomposites towards addressing this challenge. We showed that Ni3Sn2 possessed ideal hydrogen adsorption and low hydroxyl adsorption abilities and NiSnOx facilitated water dissociation and hydroxyl transfer process, respectively. Consequently, the fine‐tuned interplay of the two functional parts realized the mutual coordination among the multiple functions and led to significantly boosted HER kinetics. Current densities of 10 and 1000 mA cm−2 were obtained at overpotentials of 14 and 165 mV on the optimized catalyst. This work highlights the significance of considering intrinsic interactions between active sites and all pertinent intermediates on obtaining promising electrocatalysts. [ABSTRACT FROM AUTHOR]

The synthesis of hydrogen peroxide (H 2 O 2 ) through electrocatalytic oxygen reduction reaction is an ideal alternative to the current energy-intensive anthraquinone process, but developing cost-effective and high-efficiency electrocatalysts is still challenging. Herein, a metal-free graphitic carbon nitride/carbon nanotube (g-C 3 N 4 /CNT) hybrid catalyst can enhance H 2 O 2 production via π-π interaction is reported, achieving almost unity (97%) H 2 O 2 production at 0.57 V with high selectivity of over 92% across the wide potential range from 0.6 to 0 V. Other carbon materials with weak interaction with g-C 3 N 4 , such as acetylene black and super P, show markedly weakened H 2 O 2 production, indicating the importance of π-π interaction. Electron transfer kinetic analysis combined with density functional theory calculations indicates that the synergistic effect between g-C 3 N 4 and CNT enhances electron transfer and O 2 activation between g-C 3 N 4 and CNT, leading to enhanced H 2 O 2 production performance. This work provides a complementary approach for H 2 O 2 production from oxygen reduction besides introducing oxygenated groups or heteroatom doping into carbon materials., (© 2024 Wiley‐VCH GmbH.)

NAD(P)H cofactor is a critical energy and electron carrier in biocatalysis and photosynthesis, but the artificial reduction of NAD(P) + to regenerate bioactive 1,4-NAD(P)H with both high activity and selectivity is challenging. Herein, we found that a coupled system of a Ni 3 S 2 electrode and a Rh complex in an electrolyte (denoted as Ni 3 S 2 - Rh ) can catalyze the reduction of NAD(P) + to 1,4-NAD(P)H with superior activity and selectivity. The optimized selectivity in 1,4-NADH can be up to 99.1%, much higher than that for Ni 3 S 2 (80%); the normalized activity of Ni 3 S 2 - Rh is about 5.8 times that of Ni 3 S 2 and 13.2 times that of the Rh complex. The high performance of Ni 3 S 2 - Rh is attributed to the synergistic effect between metal sulfides and Rh complex. The NAD + reduction reaction proceeds via a concerted electron-proton transfer (CEPT) mechanism in the Ni 3 S 2 - Rh system, in which Ni 3 S 2 acts as a proton and electron-transfer mediator to accelerate the formation of Rh hydride ( Rh-H ), and then the Rh-H regioselectively transfers the hydride to NAD + to form 1,4-NADH. The artificial system Ni 3 S 2 - Rh essentially mimics the functions of ferredoxin-NADP + reductase in nature.

Identifying electrocatalysts with functions of easy dissociation of water, rapid transformation of hydroxyl and facile hydrogen-hydrogen bond formation are indispensable while challenge for realizing efficient alkaline hydrogen evolution reaction (HER). Herein, we presented the design of Ni 3 Sn 2 -NiSnO x nanocomposites towards addressing this challenge. We showed that Ni 3 Sn 2 possessed ideal hydrogen adsorption and low hydroxyl adsorption abilities and NiSnO x facilitated water dissociation and hydroxyl transfer process, respectively. Consequently, the fine-tuned interplay of the two functional parts realized the mutual coordination among the multiple functions and led to significantly boosted HER kinetics. Current densities of 10 and 1000 mA cm -2 were obtained at overpotentials of 14 and 165 mV on the optimized catalyst. This work highlights the significance of considering intrinsic interactions between active sites and all pertinent intermediates on obtaining promising electrocatalysts., (© 2023 Wiley-VCH GmbH.)