Boron induced strong metal-support interaction for high sintering resistance of Pt-based catalysts toward oxygen reduction reaction

• The highlights of this work are summarized as follows: • Synthesis of ultrasmall Pt NPs with improved sintering resistance. • Boron doping into carbon contributes to the enhanced metal-support interaction. • The method is extended to prepare PtM (M=Co, Fe, Ni, Cu) alloy NPs. • The catalysts exhibit enhanced ORR activity and stability. Insufficient thermal and electrochemical stability is a large challenge for carbon-supported Pt-based nanoparticles (NPs) as oxygen reduction reaction (ORR) catalysts. Herein, a facile pyrolysis method is developed for the synthesis of ultrasmall Pt NPs anchored on boron-doped carbon (Pt/(B-C)). The stronger interaction between Pt and boron-doped carbon (B-C) endows catalysts with improved sintering resistance to stabilize the Pt NPs of sub-3 nm up to 700 °C. The Pt/(B-C)600 catalyst presents a mass activity (MA) of 0.30 A mg Pt -1 , which is 3 times that of commercial Pt/C (0.10 A mg Pt -1 ). After durability test, the MA of the Pt/(B-C)600 catalyst has only decreased by 19.7% (commercial Pt/C dropped by 58.7%). This method can also be extended to prepare B-C supported Pt alloy NPs (PtM/(B-C), M=Co, Fe, Ni, Cu), which exhibit superior ORR performance. This study provides a general strategy for the synthesis of thermally and electrochemically stable carbon supported Pt-based catalysts.