Nitrogen-boron dipolar-doped commercial multi-walled carbon nanotubes (MWCNTs) were prepared and demonstrated as a high-efficiency and low-cost electrocatalyst for oxygen reduction reaction (ORR). The resulting nitrogen-boron dipolar-doped MWCNTs (N, B-CNTs) exhibit a doubled peak current density and a small negative shift in onset potential in ORR compared with the commercial Pt/C catalyst. The doped nitrogen and boron form n- and p-type active centers in the N, B-CNT, respectively, which can weaken the O-O stretching and extend the O-O bond length in oxygen reduction reaction. First principles calculations reveal that the O3H- and O3H2 transitional states of oxygen are formed on the doped nitrogen and boron, which promotes the four-electron reaction in ORR. (C) 2016 Elsevier Ltd. All rights reserved.