Electronic and Potential Synergistic Effects of Surface-Doped P–O Species on Uniform Pd Nanospheres: Breaking the Linear Scaling Relationship toward Electrochemical Oxygen Reduction

• DOI: 10.1021/acsami.1c22935
• Publication Date: 2022-03-15T14:13:49Z
• Authors: Liuxuan Luo; Cehuang Fu; Yangge Guo; Qi Kang; Aiming Wu; Xiyang Cai; Lutian Zhao; Zehao Tan; Jiewei Yin; Guofeng Xia; Shuiyun Shen; Junliang Zhang
• Keywords: 02 engineering and technology; 0210 nano-technology; 7. Clean energy

Developing efficient oxygen reduction reaction (ORR) electrocatalysts is critical to fuel cells and metal-oxygen batteries, but also greatly hindered by the limited Pt resources long-standing linear scaling relationship (LSR). In this study, ∼6 nm highly uniform Pd nanospheres (NSs) having surface-doped (SD) P-O species are synthesized evenly anchored onto carbon blacks, which further simply heat-treated (HT). Under alkaline conditions, Pd/SDP-O NSs/C-HT exhibits respective 8.7 (4.3)- 5.0 (5.5)-fold enhancements in noble-metal-mass- area-specific activity (NM-MSA ASA) compared with commercial Pd/C (Pt/C). It possesses an improved electrochemical stability. Besides, its acidic ASA NM-MSA 2.9 5.1 times those of Pd/C, respectively, reach 65.4 51.5% Pt/C. Moreover, it shows nearly ideal 4-electron ORR pathways under both conditions. The detailed experimental theoretical analyses reveal following: (1) electronic effect induced can downshift surface d-band center weaken intermediate adsorptions, thus preserving more active sites. (2) More importantly, potential hydrogen bond between O atom H hydrogen-containing intermediates turn stabilize their breaking LSR toward ORRs pathways. This study develops a low-cost high-performance electrocatalyst proposes promising strategy for LSR, may be applied other electrocatalysis.