Synergistic Cu@Ni–N–C Yolk@Shell Nanostructure Catalyst for Selective Acetonitrile Electroreduction to Ethylamine

Abstract Electrochemical upgrading, such as acetonitrile (CH 3 CN) reduction to ethylamine (CH 3 CH 2 NH 2 , EtNH 2 ), represents a promising route for the mild synthesis of value‐added chemicals with renewable energy sources. However, a lack of an in‐depth understanding of the hydrogenation mechanism hinders the rational development of efficient electrocatalysts to boost EtNH 2 electrosynthesis. Here, an innovative confinement strategy is reported to an efficient yolk@shell‐structured Cu@Ni–N–C catalyst, comprising inner Cu nanorods and outer atomically‐dispersed Ni on a nitrogen‐doped carbon layer, for high‐performance electrochemical CH 3 CN reduction toward CH 3 CH 2 NH 2 generation. The introduction of Ni–N–C tailors the electronic structure of Cu, and more importantly, turns its reaction pathway from a direct electroreduction (DER) mechanism into a more favorable electrochemical hydrogenation (ECH) mechanism, where * H intermediate is first generated at outer Ni–N–C layer through the proton‐coupled electron transfer process and then interacts with the adsorbed CH 3 CN molecules at inner Cu nanorods. As a consequence, the kinetic energy barrier of electrochemical CH 3 CN reduction is significantly reduced, thereby leading to a boosted activity, selectivity, and stability of Cu@Ni–N–C electrocatalyst with respect to bare Cu counterpart. This work provides insights into the rational design of synergistic yolk@shell catalysts for multi‐step electrochemical upgrading reactions with an optimized hydrogenation mechanism.