Electrochemical reduction of nitrite to ammonia on amorphous MoO3 nanosheets

Abstract

Electrocatalytic NO₂⁻ reduction to NH₃ (NO₂RR) is an appealing approach for mitigating NO₂⁻ pollution and for the synthesis of valuable NH₃, and so the exploration for high-performance NO₂RR catalysts is pivotal yet remains challenging. Herein, amorphous MoO₃ nanosheets (am-MoO₃) were designed as a high-performance NO₂RR electrocatalyst, delivering a maximum NO₂⁻-to-NH₃ faradaic efficiency of 94.8% and NH₃ yield rate of 480.4 μmol h⁻¹ cm⁻² at −0.6 V vs. RHE. Theoretical computations revealed that the largely enhanced NO₂RR activity of am-MoO₃ originated from the amorphization-induced O-vacancies, which could enhance the NO₂⁻-to-NH₃ reaction energetics and hamper the competitive hydrogen evolution.