Electrochemical transformation processes involving carbon, hydrogen, oxygen, nitrogen, and small‐molecule chemistries represent a promising means to store renewable energy sources in the form of chemical energy. However, their widespread deployment is hindered by a lack of efficient, selective, durable, and affordable electrocatalysts. Recently, grain boundary (GB) engineering as one category of defect engineering, has emerged as a viable and powerful pathway to achieve improved electrocatalytic performances. This review presents a timely and comprehensive overview of recent advances in GB engineering for efficient electrocatalysis. The beneficial effects of introducing GBs into electrocatalysts are discussed, followed by an overview of the synthesis and characterization of GB‐enriched electrocatalysts. Importantly, the latest developments in leveraging GB engineering for enhanced electrocatalysis are thoroughly examined, focusing on the electrochemical utilization cycles of carbon, hydrogen, oxygen, and nitrogen. Future research directions are proposed to further advance the understanding and application of GB engineering for improved electrocatalysis. image

An efficient and cost-effective oxygen evolution reaction (OER) electrocatalyst is key for electrochemical energy generation and storage technologies. Here, the rational design and in situ formation of an antiperovskite-based hybrid with a porous conductive Cu_1−xNNi_3−y (x and y represent defect) core and amorphous FeNiCu (oxy)hydroxide shell is reported as a promising water oxidation electrocatalyst, showing outstanding performance. Benefiting from the unique advantage of core–shell structure, as well as the synergistic effect of Fe, Ni, and Cu and the highly porous hierarchical structure, the hybrid catalyst exhibits highly efficient and robust OER performance in alkaline environments, outperforming the benchmark IrO₂ catalyst in several aspects. Our findings demonstrate the application potential of antiperovskite-based materials in the field of electrocatalysis, which may inspire insights into the development of novel materials for energy generation and storage applications.