  Electrocatalytic hydrogenation of nitrobenzene (Ph-NO2) reaction (EHNR) has
been considered as a potential alternative to the traditional thermocatalytic
process in the production of high-value aniline (Ph-NH2). However, due to the
absence of robust catalyst and low surface H* coverage, the EHNR faces the
challenges of undesired performance and indetermined mechanism. Herein, we
construct a type of noble-metal free topological FeSi (M-FeSi) materials
through a solvent-free microwave strategy for efficient EHNR in neutral medium.
Impressively, benefiting from abundant active H* intermediates on the surface
of M-FeSi catalyst, the topological M-FeSi catalyst exhibits 99.7% conversion
of Ph-NO2 and 93.8% yield of Ph-NH2 after 200 C in neutral medium, which are
superior to previous candidates and FeSi catalyst synthesized via the
traditional arc-melting method under same conditions. Besides, theoretical
calculations validate that high surface H* coverage over M-FeSi catalyst is
conducive to switching the rate-determining step from Ph-NO2* Ph-NO* to Ph-NO*
Ph-NHOH*, and thus decreasing the total energy barrier of electrocatalytic
Ph-NH2 production.
