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The rational fabrication of Pt‐free catalysts for driving the development of practical applications in alkaline water electrolysis and fuel cells is promising but challenging. Herein, a promising approach is outlined for the rational design of multimetallic catalysts comprising multiple active sites including Pd nanoclusters and Ru single atoms anchored at the defective sites of Ni(OH)2 to simultaneously enhance hydrogen evolution reactions (HER) and ethanol oxidation reactions (EOR). Remarkably, Pd12Ru3/Ni(OH)2/C exhibits a remarkably reduced HER overpotential (16.1 mV@10 mA cm−2 with a Tafel slope of 21.8 mV dec−1) as compared to commercial 20 wt.% Pt/C (26.0 mV@10 mA cm−2, 32.5 mV dec−1). More importantly, Pd12Ru3/Ni(OH)2/C possesses a self‐optimized overpotential to 12.5 mV@10 mA cm−2 after 20 000 cycles stability test while a significantly decreased performance for commercial 20wt.% Pt/C (64.5 mV@10 mA cm−2 after 5000 cycles). The mass activity of Pd12Ru3/Ni(OH)2/C for the EOR is up to 3.724 A mgPdRu−1, ≈20 times higher than that of commercial Pd/C. Electrochemical in situ Fourier transform infrared measurements confirm the enhanced CO2 selectivity of Pd12Ru3/Ni(OH)2/C while synergistic and electronic effects of adjacent Ru, Pd, and OHad adsorption on Ni(OH)2 at low potential play a key role during EOR. [ABSTRACT FROM AUTHOR]

The electrocatalytic urea oxidation reaction (UOR) provides more economic electrons than water oxidation for various renewable energy‐related systems owing to its lower thermodynamic barriers. However, it is limited by sluggish reaction kinetics, especially by CO2 desorption steps, masking its energetic advantage compared with water oxidation. Now, a lattice‐oxygen‐involved UOR mechanism on Ni4+ active sites is reported that has significantly faster reaction kinetics than the conventional UOR mechanisms. Combined DFT, 18O isotope‐labeling mass spectrometry, and in situ IR spectroscopy show that lattice oxygen is directly involved in transforming *CO to CO2 and accelerating the UOR rate. The resultant Ni4+ catalyst on a glassy carbon electrode exhibits a high current density (264 mA cm−2 at 1.6 V versus RHE), outperforming the state‐of‐the‐art catalysts, and the turnover frequency of Ni4+ active sites towards UOR is 5 times higher than that of Ni3+ active sites. [ABSTRACT FROM AUTHOR]

[Display omitted] • Oxygen etching was used at 250 °C to produce MOF-derived nickel/carbon SAC (Ni 1 @C-250A) without nanoparticles. • Ni 1 @C-250A exhibits faradaic efficiency of ∼ 100% for producing syngas with the high stability. • The CO/H 2 ratio of syngas can be adjusted in a wide range from 1.5:1 to 4.3:1. Metal single-atom catalysts (SACs) supported on carbon mainly produce syngas in electrochemical CO 2 reduction reaction (CO 2 RR), in comparison with the dominant H 2 production on nanoparticles. However, it is a major challenge to prepare the carbon-supported SACs without the presence of nanoparticles using conventional pyrolysis. Here, we report the approach involving oxygen etching at 250 °C to produce MOF-derived nickel/carbon SAC (Ni 1 @C-250A). The combination of oxygen etching with acid treatment completely removes the Ni nanoparticles, only showing the existence of single-atom Ni species. In CO 2 RR, the Ni 1 @C-250A exhibits excellent faradaic efficiency (FE) of ∼ 100% for syngas production with the excellent stability for 360 min time-on-stream. In addition, the CO/H 2 ratio can be adjusted in a wide range from 1.5:1 to 4.3:1. This approach involving oxygen etching offers a promising strategy to dominantly produce SACs used for CO 2 RR to generate syngas, which is an important platform feedstock for the utilization of carbon-based energy. [ABSTRACT FROM AUTHOR]