Molecular hydrogen has been considered as ideal energy carrier due to its high calorific value and clean product, which also requires eco-friendly generation process. Electrocatalytic H 2 evolution from water splitting represents a compelling sustainable and green energy technology, but it is severely hindered by the large overpotential needed, especially for non-noble metal electrocatalysts. In this study, an interface engineering strategy is extended to improve the catalytic hydrogen evolution reaction (HER) performance of CoP by introducing CeO 2 component. The novel heterostructure of CoP/CeO 2 is successfully fabricated by a selective phosphidation treatment of pre-synthesized Co-PBA/CeO 2 hybrid precursor. The introduced CoP/CeO 2 hetero-interface would regulate the electronic structure, accelerate charge transfer and enhance the intrinsic activity of the active sites. By optimizing the content of functional CeO 2 entity, the CoP/CeO 2 -2.5 is the most active electrocatalyst with the lowest overpotential of 152 mV to reach 10 mA cm−2 current in 1.0 M KOH, as well as a Tafel slope of 83.5 mV dec−1. Besides, CoP/CeO 2 -2.5 can also continuously operate well for more than 16 h, demonstrating the good durability of this electrocatalyst. This work would broaden the advanced HER electrocatalysts by fabricating hetero-interface with different functional components. [Display omitted] • Heterostructural CoP/CeO 2 electrocatalysts were fabricated via phosphidation treatment of Co-PBA/CeO 2 templates. • The CeO 2 engaged interface can accelerate charge transfer, expose more active sites and enhance the intrinsic activity. • The CoP/CeO 2 -2.5 electrocatalyst exhibits only 152 mV overpotential to drive 10 mA cm−2 current towards HER. [ABSTRACT FROM AUTHOR]