Efficient dinitrogen fixation on porous covalent organic framework/carbon nanotubes hybrid at low overpotential

摘要

Electrocatalytic nitrogen reduction under ambient conditions is a promising approach for ammonia synthesis, but it is challenging to develop highly efficient electrocatalysts. In this work, a hybrid of covalent organic framework (COF) and carbon nanotubes (CNTs) are developed for efficient nitrogen electroreduction with a high faradaic efficiency (FE) of 12.7% at 0.0 V versus reversible hydrogen electrode (RHE) and a remarkable production rate of ammonia up to 8.56 mu g h(-1) mg cat(-1) at -0.2 V versus RHE. Experiments and theoretical calculations reveal that Ni centers are active sites for NH3 synthesis, while the pi-pi stacking between COF-366-Ni and conductive CNTs scaffold results in the rapid interfacial charge transfer. This investigation provides new insights on the rational design of organic-inorganic porous hybrids for efficient nitrogen conversion and ammonia synthesis at ambient conditions.