i-WO_x catalyst exhibited record fast reaction kinetics (440 mA cm^-2 at 1.6 V versus reversible hydrogen electrode) and a high turnover frequency of 0.11 s^-1 , which is 4.8 times higher than that without W dopants. In further experiments, we found that the W dopant regulated the local charge distribution of Ni atoms, leading to the formation of Ni³⁺ sites with superior activity and thus accelerating the interfacial catalytic reaction. Moreover, when we integrated Ni-WO_x into a CO₂ flow electrolyzer, the cell voltage is reduced to 2.16 V accompanying with ≈98 % Faradaic efficiency towards carbon monoxide.1f:T428,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, ¹⁸ O 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.

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