Abstract: Frustrated Lewis pairs (FLP), as a new class of catalysts, combine their excellent catalytic performance with the advantage of easy separation and recycling of heterogeneous catalysts, showing great potential in the field of activation and conversion of small molecules. However, the development of heterogeneous FLP catalysts with high activity, high surface density, and high stability remains a challenge. We focused on the key issues of the electrochemical reduction of nitrate (NO3RR) to synthesize ammonia at room temperature: the adsorption and activation of NO3-, as well as the provision of sufficient active hydrogen to accelerate the hydrogenation process. We designed and prepared N-doped TiO2-x supported by Zr single atoms (Zr-TiON). By taking advantage of its rich oxygen vacancies (Ov), unsaturated Zr (Lewis acid, LA) sites and the oxygen atoms (Lewis base, LB) around the Ov, frustrated Lewis pairs (FLPs) were constructed. Under the condition of -60 mA cm-2, the Faraday efficiency of NH3 reached 94.8%, and the productivity was 663.15 µmol h-1 mgcat-1. In a flow electrolyzer at -1 A cm-2, the yield was as high as 26.16 mmol h-1 mgcat-1. Theoretical calculations and in-situ spectroscopic analysis showed that the interaction between the LA and LB sites in FLPs plays a crucial role in promoting the adsorption and activation of electron-rich NO3- and electron-deficient *H. The presence of enhanced FLPs significantly reduces the dissociation energy barrier of H2O, decreasing it to 0.20 eV, thus promoting the subsequent hydrogenation reaction. The abundant *H can accelerate the hydrogenation process, thereby improving the activity of NO3RR. This FLP design paves the way for the development of highly efficient NO3RR catalysts and is a promising approach.