Synergy of Pd 2+ /S 2- Doped TiO 2 Supported on 2-methylimidazolium Functionalized Polypyrrole/Graphene Oxide for Enhanced Nitrogen Electro-Oxidation.

The electrosynthesis of nitrate catalyzed by electrochemical nitrogen oxidation reaction (NOR) had been considered as an alternative and sustainable approach to the conventional industrial manufacture, but optimizing the electrocatalytic NOR performance and fabricating the efficient NOR electrocatalysts at the design level still encountered great challenges. Herein, unique Pd 2+ and S 2- doped TiO 2 (Pb/S-TiO 2 ) nanoparticles had successfully in situ grown on the surface of 2-methylimidazolium functionalized polypyrrole/graphene oxide (2-MeIm/PPy/GO), which presented the typical hierarchical micro-nanostructures, resulting in the excellent electrocatalytic NOR performance with the highest NO 3 - yield of 72.69 µg h -1 mg -1 act. and the maximum FE of 8.92% at 2.04 V (versus RHE) due to the synergistic effect of each component. Due to the doping effect, the appropriate oxygen evolution reaction (OER) activity was achieved by Ti-site, where OER principally occurred, providing *O during the non-electrochemical step of NOR, while the electrocatalytic NOR process as the electrochemical conversion of inert N 2 to active *NO intermediates mainly occurred at the Pd-site. Especially, the sulfate radicals in situ formed on Pb/S-TiO 2 @2-MeIm/PPy/GO would further promote nitrogen adsorption and decreased the reaction energy barrier, resulting in the acceleration of NOR. It would provide theoretical and practical experience for the design and preparation of NOR elecctrocatalysts. This article is protected by copyright. All rights reserved.