Reactivity of nitrogen atoms from Zif-8 structure deposited over TiC MXene in the electrochemical nitrogen reduction reaction.

The electrochemical nitrogen reduction reaction (NRR) to produce NH is the most efficient, eco-friendly and cost-effective alternative to the Haber-Bosch process. It is crucial to investigate and develop electrocatalysts selective for NH synthesis. In recent studies, the TiC MXene has emerged as a highly promising electrocatalyst for the NRR process. In this work, we explore the effect of Zif-8 addition over MXene sheets in order to control the rate of hydrogen evolution reaction (HER). Despite the better result obtained for Zif-8@TiC (3.0 μg NH g h at -0.55 V/RHE), the ammonia produced when using Zif-8@TiC as cathode material is shown to be originated from nitrogen atoms contained in the Zif-8 structure instead of those of N. The results shed light to the need to fully understand the N electroreduction process over -containing electrocatalysts.