Potassium ions promote electrochemical nitrogen reduction on nano-Au catalysts triggered by bifunctional boron supramolecular assembly

Abstract

The electrochemical way of reducing nitrogen to ammonia presents green and economic advantages to dial down irreversible damage caused by the energy-intensive Haber–Bosch process. Here, we introduce an advanced catalyst CB[7]–K₂[B₁₂H₁₂]@Au with highly dispersed and ultrafine nano-gold. The CB[7]–K₂[B₁₂H₁₂]@Au electrochemically driven ammonia yield and Faraday efficiency is as high as 41.69 μg h⁻¹ mg_cat.⁻¹ and 29.53% (at −0.4 V vs. RHE), respectively, reaching the US Department of Energy (DOE) utility index of ambient ammonia production along with excellent cycle stability and tolerance that indicates a high potential of industrial practical value. Experimental results and theoretical calculations show that the key to an excellent electrochemical nitrogen reduction performance lies in the smart design of the CB[7]–K₂[B₁₂H₁₂]@Au catalyst combining the stable substrate anchored Au nanoparticles and K⁺ ions that effectively prevent the hydrogen evolution reaction and polarize *N₂ leading to lowering of the rate determining step. This research will promote the further development of electrochemical ammonia production with low environmental impact.