Assembly of Hydrophobic ZIF-8 on CeO2 Nanorods as High-Efficiency Catalyst for Electrocatalytic Nitrogen Reduction Reaction

The electrocatalytic nitrogen reduction reaction (NRR) can use renewable electricity to convert water and N-2 into NH3 under normal temperature and pressure conditions. However, due to the competitiveness of the hydrogen evolution reaction (HER), the ammonia production rate (R-NH(3)) and Faraday efficiency (FE) of NRR catalysts cannot meet the needs of large-scale industrialization. Herein, by assembling hydrophobic ZIF-8 on a cerium oxide (CeO2) nanorod, we designed an excellent electrocatalyst CeO2-ZIF-8 with intrinsic NRR activity. The hydrophobic ZIF-8 surface was conducive to the efficient three-phase contact point of N-2 (gas), CeO2 (solid) and electrolyte (liquid). Therefore, N-2 is concentrated and H+ is deconcentrated on the CeO2-ZIF-8 electrocatalyst surface, which improves NRR and suppresses HER and finally CeO2-ZIF-8 exhibits excellent NRR performance with an R-NH(3) of 2.12 mu g h(-1) cm(-2) and FE of 8.41% at -0.50 V (vs. RHE). It is worth noting that CeO2-ZIF-8 showed excellent stability in the six-cycle test, and the R-NH(3) and FE variation were negligible. This study paves a route for inhibiting the competitive reaction to improve the NRR catalyst activity and may provide a new strategy for NRR catalyst design.