Rhodium Metallene With Wrinkle‐Induced Lattice Strain for Acetonitrile Electroreduction Related Energy Conversion

ABSTRACT Metallene has been widely considered as an advanced electrocatalytic material due to its large specific surface area and highly active reaction sites. Herein, we design and synthesize ultrathin rhodium metallene (Rh ML) with abundant wrinkles to supply surface‐strained Rh sites for driving acetonitrile electroreduction to ethylamine (AER). The electrochemical tests indicate that Rh ML shows an ethylamine yield rate of 137.1 mmol gcat−1 h−1 in an acidic solution, with stability lasting up to 200 h. Theoretical calculations reveal that Rh ML with wrinkle‐induced compressive strain not only shows a lower energy barrier in the rate‐determining step but also facilitates the ethylamine desorption process compared to wrinkle‐free Rh ML and commercial Rh black. The assembled electrolyzer with bifunctional Rh ML shows an electrolysis voltage of 0.41 V at 10 mA cm−2, enabling simultaneous ethylamine production and hydrazine waste treatment. Furthermore, the voltage of an assembled hybrid zinc–acetonitrile battery can effectively drive this electrolyzer to achieve the dual AER process. This study provides guidance for improving the catalytic efficiency of surface atoms in two‐dimensional materials, as well as the electrochemical synthesis technology for series‐connected battery–electrolyzer systems.