Creating bimetallic Pt-based nanocrystals with core–shell structures has widely been recognized as the most effective way for improving their electrochemical properties. Herein, a simple one-pot synthesis method is used to prepare Ni1.1Pt nanoparticles (NPs) (~ 5.3 nm) with a nickel (Ni)-rich core and a Pt-rich thin shell (~ 1.0 nm). The Ni1.1Pt/C shows enhanced acid oxygen reduction reaction (ORR) activity with a mass activity (MA) of 661.7 mA mgPt−1 and specific activity (SA) of 1.52 mA cmPt−2, which is 4.3 and 8.4 times that of commercial JM Pt/C, respectively. In addition, Ni1.1Pt/C is also demonstrated to have better ORR stability than JM Pt/C. These excellent properties are contributed to the suitable compressive strain, appropriate electronic effects, and outstanding anti-aggregation of the core–shell structure. [ABSTRACT FROM AUTHOR]