Magneto-electrochemical ammonia synthesis: Boosting nitrite reduction activity by the optimized magnetic field induced in spin polarized system

Using low and optimized magnetic field along with electric field is a novel strategy to facilitate electrochemical nitrite reduction. Here, we report for the first time on the synthesis of ammonia via magneto-electrocatalytic methods that use spin-thrusted β-MnPc in a magnetic field of 95 mT. The calculated rate of ammonia generation was 16603.4 µg h-1 mgcat-1, which is almost twice that of the non-polarized MnPc catalyst. Additionally, the faradaic efficiency at –0.9V vs. RHE was found to be 92.9%, significantly higher compared to the non-polarized MnPc catalyst. In presence of external magnetic field, MnPc catalysts provide a better electron transfer channel which results in a lower charge transfer resistance and hence better electrochemical performances. DFT result further verifies that magnetic field induced β-MnPc has a lower potential barrier (0.51 eV) for the protonation of NO* (PDS) than non-polarized β-MnPc (1.08 eV), which confirms the enhanced electrochemical nitrite reduction to ammonia aided by external magnetic field.