This article presents a study on the efficient electroreduction of nitrite (NO₂⁻) to ammonia (NH₃) using a Zr-NiO catalyst. The catalyst features atomically dispersed Zr-dopants in the NiO lattice, enabling high-performance NO₂⁻ to NH₃ conversion with industrial-level current density (>0.2 A cm⁻²). In situ spectroscopic measurements and theoretical simulations reveal the formation of Zr-Ni frustrated Lewis acid-base pairs (FLPs), which enhance nitrite absorption, activation, and protonation, while reducing hydrogen coverage. The Zr-NiO catalyst demonstrates exceptional performance in a flow cell, achieving a Faradaic efficiency for NH₃ of 94.0% and an NH₃ yield rate of 1,394.1 μmol h⁻¹ cm⁻² at an industrial-level current density of 228.2 mA cm⁻², making it one of the best NO₂⁻ to NH₃ electrocatalysts. Ammonia is crucial for producing fertilizers, pharmaceuticals, and dyes, and is also a potential carbon-free energy carrier. However, the Haber-Bosch process for ammonia synthesis is energy-intensive and contributes to carbon emissions. Electrochemical ammonia synthesis via nitrogen reduction has gained attention, but its efficiency is limited by high reaction barriers and competing hydrogen evolution reactions. Nitrite is a key intermediate in the nitrogen cycle and a common pollutant. Converting nitrite to ammonia through electrocatalysis is significant for addressing public health and energy issues. However, the NO₂⁻ to NH₃ reaction (NO₂RR) is inefficient due to high activation barriers and side reactions. Various catalysts, including metal oxides and carbon materials, have been explored, but their performance remains unsatisfactory for practical ammonia synthesis. Surface FLPs, consisting of paired Lewis acid and base sites, have shown promise in activating small molecules and enhancing electrocatalytic reactions. Inspired by this, constructing FLPs on catalysts is a promising strategy for NO₂⁻ activation and electroreduction. The study reports the synthesis of Zr-NiO nanoflowers containing Zr-Ni₄ FLPs, which exhibit exceptional performance in a flow cell. The catalyst's activity origins and structure-property relations are further studied using atom-level characterizations, in situ spectroscopy, and theoretical calculations. The preparation process and characterization of Zr-NiO and bare NiO nanoflowers are detailed, showing the uniform dispersion of Zr on the NiO substrate and the formation of a nanoflower structure. The study highlights the potential of Zr-NiO as an efficient catalyst for NO₂⁻ to NH₃ electroreduction.This article presents a study on the efficient electroreduction of nitrite (NO₂⁻) to ammonia (NH₃) using a Zr-NiO catalyst. The catalyst features atomically dispersed Zr-dopants in the NiO lattice, enabling high-performance NO₂⁻ to NH₃ conversion with industrial-level current density (>0.2 A cm⁻²). In situ spectroscopic measurements and theoretical simulations reveal the formation of Zr-Ni frustrated Lewis acid-base pairs (FLPs), which enhance nitrite absorption, activation, and protonation, while reducing hydrogen coverage. The Zr-NiO catalyst demonstrates exceptional performance in a flow cell, achieving a Faradaic efficiency for NH₃ of 94.0% and an NH₃ yield rate of 1,394.1 μmol h⁻¹ cm⁻² at an industrial-level current density of 228.2 mA cm⁻², making it one of the best NO₂⁻ to NH₃ electrocatalysts. Ammonia is crucial for producing fertilizers, pharmaceuticals, and dyes, and is also a potential carbon-free energy carrier. However, the Haber-Bosch process for ammonia synthesis is energy-intensive and contributes to carbon emissions. Electrochemical ammonia synthesis via nitrogen reduction has gained attention, but its efficiency is limited by high reaction barriers and competing hydrogen evolution reactions. Nitrite is a key intermediate in the nitrogen cycle and a common pollutant. Converting nitrite to ammonia through electrocatalysis is significant for addressing public health and energy issues. However, the NO₂⁻ to NH₃ reaction (NO₂RR) is inefficient due to high activation barriers and side reactions. Various catalysts, including metal oxides and carbon materials, have been explored, but their performance remains unsatisfactory for practical ammonia synthesis. Surface FLPs, consisting of paired Lewis acid and base sites, have shown promise in activating small molecules and enhancing electrocatalytic reactions. Inspired by this, constructing FLPs on catalysts is a promising strategy for NO₂⁻ activation and electroreduction. The study reports the synthesis of Zr-NiO nanoflowers containing Zr-Ni₄ FLPs, which exhibit exceptional performance in a flow cell. The catalyst's activity origins and structure-property relations are further studied using atom-level characterizations, in situ spectroscopy, and theoretical calculations. The preparation process and characterization of Zr-NiO and bare NiO nanoflowers are detailed, showing the uniform dispersion of Zr on the NiO substrate and the formation of a nanoflower structure. The study highlights the potential of Zr-NiO as an efficient catalyst for NO₂⁻ to NH₃ electroreduction.