The modulation of catalytic active site and support to construct high-efficiency ZnS/NC-X electrocatalyst for nitrogen reduction

Transition metals are a kind of promising catalysts to apply into electrocatalytic synthesis ammonia by virtue of abundant reserves and low cost. However, many widely used transition metal catalysts usually face the challenge to realize satisfactory catalytic results mainly resulting from the match between catalytic active site and support. Here, a new-type ZnS/NC-X electrocatalyst was reported by in-situ sulfidation of zeolitic imidazolate framework-8 (ZIF-8), where the metal nodes of ZIF-8 reacted with dibenzyl disulfide (BDS) to obtain ZnS nanoparticles and the framework of ZIF-8 was carbonized to form the support. Especially, catalytic active sites (ZnS nanoparticles) and support (NC-X) were adjusted in detailed by changing the ratio of ZIF-8 and BDS. As a result, when the mass ratio of ZIF-8 and BDS was 1:1, the resulted ZnS/NC-2 catalyst achieved a remarkable NH₃ yield of 65.60 μg·h⁻¹·mg⁻¹_cat., Faradaic efficiency (FE) of 18.52% at −0.4 V vs reversible hydrogen electrode (RHE) in 0.05 M H₂SO₄ and catalytic stability, which outperformed most reported transition metal sulfides. The matching catalytic active site and support make our strategy promising for wide catalytic applications.