Spin-engineered Cu–Ni metallic aerogels for enhanced ethylamine electrosynthesis from acetonitrile

Abstract

Spin engineering is an effective strategy to improve the performance of catalysts, but it has been rarely demonstrated for the acetonitrile reduction reaction (ARR) to date. Herein, for the first time, we prepared a series of composition controllable Cu–Ni metallic aerogels (MAs) with a spin effect for acetonitrile electroreduction. Due to the optimal d electron filling, among the different catalysts, Cu₃Ni₁ MAs showed the highest ethylamine selectivity and yield rate of 98.01% and 173.2 μmol h⁻¹ at −0.65 V_RHE, respectively, as well as an ethylamine Faraday efficiency of 95.49% at −0.45 V_RHE, which was superior to Cu₃Ni₁ nanoparticles (NPs) (79.83%, 105.7 μmol h⁻¹, and 81.86%). Meanwhile, Cu₃Ni₁ MAs still exhibited a yield rate of ethylamine of 200.9 μmol h⁻¹ under the commercial flow cell test. Based on in situ spectral studies, we show that the significantly boosted production resulted from the unique structure and high spin state of Cu₃Ni₁ MAs, which could optimize the adsorption of acetonitrile molecules and the imine intermediate, in which the reaction between the imine intermediate and the dissociative ethylamine was prevented, and the primary amine was also protected. The present work demonstrates that spin engineering can play an important role in promoting ARR performance and provides a new strategy for creating efficient ARR electrocatalysts.