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The development of environmentally sustainable and highly efficient technologies for ammonia production is crucial for the future advancement of carbon‐neutral energy systems. The nitrite reduction reaction (NO2RR) for generating NH3 is a promising alternative to the low‐efficiency nitrogen reduction reaction (NRR), owing to the low N=O bond energy and high solubility of nitrite. In this study, we designed a highly efficient dual‐atom catalyst with Fe‐Cu atomic pair sites (termed FeCu DAC), and the as‐developed FeCu DAC was able to afford a remarkable NH3 yield of 24,526 μg h−1 mgcat.−1 at −0.6 V, with a Faradaic Efficiency (FE) for NH3 production of 99.88 %. The FeCu DAC also exhibited exceptional catalytic activity and selectivity in a Zn‐NO2 battery, achieving a record‐breaking power density of 23.6 mW cm−2 and maximum NH3 FE of 92.23 % at 20 mA cm−2. Theoretical simulation demonstrated that the incorporation of the Cu atom changed the energy of the Fe 3d orbital and lowered the energy barrier, thereby accelerating the NO2RR. This study not only demonstrates the potential of galvanic nitrite‐based cells for expanding the field of Zn‐based batteries, but also provides fundamental interpretation for the synergistic effect in highly dispersed dual‐atom catalysts. [ABSTRACT FROM AUTHOR]

The development of environmentally sustainable and highly efficient technologies for ammonia production is crucial for the future advancement of carbon-neutral energy systems. The nitrite reduction reaction (NO 2 RR) for generating NH 3 is a promising alternative to the low-efficiency nitrogen reduction reaction (NRR), owing to the low N=O bond energy and high solubility of nitrite. In this study, we designed a highly efficient dual-atom catalyst with Fe-Cu atomic pair sites (termed FeCu DAC), and the as-developed FeCu DAC was able to afford a remarkable NH 3 yield of 24,526 μg h -1 mg cat. -1 at -0.6 V, with a Faradaic Efficiency (FE) for NH 3 production of 99.88 %. The FeCu DAC also exhibited exceptional catalytic activity and selectivity in a Zn-NO 2 battery, achieving a record-breaking power density of 23.6 mW cm -2 and maximum NH 3 FE of 92.23 % at 20 mA cm -2 . Theoretical simulation demonstrated that the incorporation of the Cu atom changed the energy of the Fe 3d orbital and lowered the energy barrier, thereby accelerating the NO 2 RR. This study not only demonstrates the potential of galvanic nitrite-based cells for expanding the field of Zn-based batteries, but also provides fundamental interpretation for the synergistic effect in highly dispersed dual-atom catalysts., (© 2023 Wiley-VCH GmbH.)

The alkaline hydrogen evolution reaction (HER) in an anion exchange membrane water electrolyzer (AEMWE) is considered to be a promising approach for large-scale industrial hydrogen production. Nevertheless, it is severely hampered by the inability to operate tolerable HER catalysts consistently under low overpotentials at ampere-level current densities. Here, we develop a universal ligand-exchange (MOF-on-MOF) modulation strategy to synthesize ultrafine Fe 2 P and Co 2 P nanoparticles, which are well anchored on N and P dual-doped carbon porous nanosheets (Fe 2 P-Co 2 P/NPC). In addition, benefiting from the downshift of the d-band center and the interfacial Co-P-Fe bridging, the electron-rich P site is triggered, which induces the redistribution of electron density and the swapping of active centers, lowering the energy barrier of the HER. As a result, the Fe 2 P-Co 2 P/NPC catalyst only requires a low overpotential of 175 mV to achieve a current density of 1000 mA cm -2 . The solar-driven water electrolysis system presents a record-setting and stable solar-to-hydrogen conversion efficiency of 20.36%. Crucially, the catalyst could stably operate at 1000 mA cm -2 over 1000 h in a practical AEMWE at an estimated cost of US$0.79 per kilogram of H 2 , which achieves the target (US$2 per kg of H 2 ) set by the U.S. Department of Energy (DOE).

Designing high-efficiency and low-cost catalysts with high current densities for the oxygen evolution reaction (OER) is critical for commercial seawater electrolysis. Here, we present a heterophase synthetic strategy for constructing an electrocatalyst with dense heterogeneous interfacial sites among crystalline Ni 2 P, Fe 2 P, CeO 2 , and amorphous NiFeCe oxides on nickel foam (NF). The synergistic effect of high-density crystalline and amorphous heterogeneous interfaces effectively promotes the redistribution of the charge density and optimizes the adsorbed oxygen intermediates, lowering the energy barrier and promoting the O 2 desorption, thus enhancing the OER performance. The obtained NiFeO-CeO 2 /NF catalyst exhibited outstanding OER catalytic activity, with low overpotentials of 338 and 408 mV required to attain high current densities of 500 and 1000 mA cm -2 , respectively, in alkaline natural seawater electrolytes. The solar-driven seawater electrolysis system presents a record-setting and stable solar-to-hydrogen conversion efficiency of 20.10%. This work provides directives for developing highly effective and stable catalysts for large-scale clean energy production.