Segmentation and Re-encapsulation of Porous PtCu Nanoparticles by Generated Carbon Shell for Enhanced Ethylene Glycol Oxidation and Oxygen-Reduction Reaction

Juanjuan Gao; Mengxi Mao; Peiwen Li; Rumeng Liu; Haiou Song; Kuan Sun; Shupeng Zhang

doi:10.1021/acsami.9b20504

Segmentation and Re-encapsulation of Porous PtCu Nanoparticles by Generated Carbon Shell for Enhanced Ethylene Glycol Oxidation and Oxygen-Reduction Reaction

ACS Appl Mater Interfaces. 2020 Feb 5;12(5):6298-6308. doi: 10.1021/acsami.9b20504. Epub 2020 Jan 22.

Authors

Juanjuan Gao^{1

2}, Mengxi Mao¹, Peiwen Li¹, Rumeng Liu¹, Haiou Song³, Kuan Sun⁴, Shupeng Zhang¹

Affiliations

¹ School of Chemical Engineering , Nanjing University of Science and Technology , Nanjing 210094 , P. R. China.
² School of Chemistry and Chemical Engineering , Yancheng Institute of Technology , Yancheng 224051 , P. R. China.
³ School of Environment , Nanjing Normal University , Nanjing 210097 , P. R. China.
⁴ MOE Key Laboratory of Low-grade Energy Utilization Technologies and Systems, School of Energy & Power Engineering , Chongqing University , Chongqing 400044 , P. R. China.

PMID: 31927902
DOI: 10.1021/acsami.9b20504

Abstract

Hierarchical porous carbon-encapsulated ultrasmall PtCu (UsPtCu@C) nanoparticles (NPs) were constructed based on segmentation and re-encapsulation of porous PtCu NPs by using glucose as a green biomass carbon source. The synergistic electronic effect from the bimetallic elements can enhance the catalytic activity by adjusting the surface electronic structure of Pt. Most importantly, the generated porous carbon shell provided a large contact surface area, excellent electrical conductivity, and structural stability, and the ultrasmall PtCu NPs exhibited an increased electrochemical performance compared with their PtCu matrix because of the exposure of more catalytically active centers. This synergistic relationship between the components resulted in enhanced catalytic activity and better stability of the obtained UsPtCu@C for ethylene glycol oxidation reaction and the oxygen-reduction reaction in alkaline electrolyte, which was higher than the PtCu NPs and commercial Pt/C (20 wt % Pt on Vulcan XC-72). The electrochemically active surface areas of the UsPtCu@C, PtCu NPs, and commercial Pt/C were calculated to be approximately 230.2, 32.8, and 64.0 m²/g_Pt, respectively; the mass activity of the UsPtCu@C for the ethylene glycol oxidation reaction was 8.5 A/mg_Pt, which was 14.2 and 8.5 times that of PtCu NPs and commercial Pt/C, respectively. The specific activity of UsPtCu@C was 3.7 mA/cm_pt², which was 2.1 and 2.3 times that of PtCu NPs and commercial Pt/C, respectively. The onset potential (E_on-set) of UsPtCu@C for the oxygen-reduction reaction was 0.96 V (vs reversible hydrogen electrode, RHE), which was 110 and 60 mV higher than PtCu and commercial Pt/C, respectively. The half-wave potentials (E_1/2) of UsPtCu@C, PtCu, and Pt/C were 0.88, 0.56, and 0.82 V (vs RHE), respectively, which indicated that the UsPtCu@C catalyst had an excellent bifunctional electrocatalytic activity.

Keywords: electrocatalytic performance; ethylene glycol oxidation reaction; oxygen-reduction reaction; porous carbon; ultrasmall PtCu.