High-Efficiency Electrocatalytic Conversion of Nitrite to Ammonia Using Nickel Phthalocyanine

Abstract

Nitrite (NO2−) is a dangerous pollutant that is often found in groundwater sources and endangers human health. In addition to nitrite removal requirements, electrocatalytic nitrite reduction reaction (eNO2RR) holds promise for value-added ammonia (NH3) production at room temperature. In this study, a solvothermal technique for the preparation of nickel phthalocyanine (NiPc) is used as a highly active electrocatalyst for the conversion of NO2− to NH3 under ambient conditions. The NiPc catalyst shows a remarkable Faradaic efficiency (FE) of 90.1% at −0.9 V versus RHE with maximum ammonia yield rate of 14667 µg h−1 mgcat.−1 at −1.0 V versus RHE in 0.1 M Na2SO4 containing 0.1 M NaNO2 solution. Furthermore, the catalyst exhibits exceptional long-term stability during chronoamperometry tests. These findings boost the future ammonia production from nitrite reduction for sustainable development.