Electrosynthesis of nitrate by Pd and TiO2 nanoparticles anchored on 2-methylimidazolium functionalized polypyrrole/graphene oxide

Though a very simple method, a small quantity of Pd and TiO2 nanoparticles have been in-situ grown on 2-methylimidazolium functionalized polypyrrole/graphene oxide (2-MeIm/PPy/GO), which can be confirmed by several characterization analysis. The obtained Pd&TiO2@2-MeIm/PPy/GO nanosheets exhibit good nitrogen oxidation reaction (NOR) electroactivity with the excellent stability and selectivity, due to the concerted catalysis of Pd and TiO2 with super-small size. Pd with high nitrogen activation capacity and TiO2 with low oxygen evolution reaction (OER) electroactivity are combined to the benefit of electrocatalytic NOR process. The optimal potential for NOR by Pd&TiO2@2-MeIm/PPy/GO is 2.04 V versus the reversible hydrogen electrode, with the corresponding nitrate yield and Faraday efficiency are 12.60 μg h−1 mg−1cat. and 4.04 %, respectively. No NO3− is detected in Ar-saturated electrolyte, indicating the generation of the detected NO3− deriving from the electrocatalytic oxidation of N2.