Noncovalent composites of meso-substituted A2B2-porphyrins and carbon nanotubes for enhanced electrocatalytic oxygen reduction

Yue Zhao; Zhen-Yu Huang; Wan-Yue Xie; Si-Jing Huang; Bei Wan; Wei-Chang Chen; Hai-Yang Liu; Li-Ping Si

doi:10.1088/1361-6528/acf720

Noncovalent composites of meso-substituted A₂B₂-porphyrins and carbon nanotubes for enhanced electrocatalytic oxygen reduction

Nanotechnology. 2023 Sep 25;34(49). doi: 10.1088/1361-6528/acf720.

Authors

Yue Zhao¹, Zhen-Yu Huang¹, Wan-Yue Xie¹, Si-Jing Huang², Bei Wan¹, Wei-Chang Chen¹, Hai-Yang Liu¹, Li-Ping Si^{1

3}

Affiliations

¹ School of Chemistry and Chemical Engineering, The Key Laboratory of Fuel Cell Technology of Guangdong Province, South China University of Technology, Guangzhou 510640, People's Republic of China.
² Analytical and Testing Center, South China University of Technology, Guangzhou 510641, People's Republic of China.
³ School of Materials Science and Energy Engineering, Foshan University, Foshan 528000, People's Republic of China.

PMID: 37673043
DOI: 10.1088/1361-6528/acf720

Abstract

Exploring highly active oxygen reduction electrocatalysts with low precious metals content is imperative but remains a considerable challenge. Herein, a series of heterobimetallic multi-walled carbon nanotubes (MWCNTs) electrocatalysts based on metal complexes are presented. These electrocatalysts feature diverse transition metals (M=Mn, Fe, Co, Ni) 5,15-bromophenyl-10, 20-methoxyphenyl porphyrin (MBMP) and tetrakis(triphenylphosphine)palladium (0) (Pd[P(Ph₃)₄]) anchored non-covalently on its surface. The resulting NiBMP-based MWCNTs with Pd[P(Ph₃)₄] (PdNiN4/MWCNTs) display outstanding electrocatalytic oxygen reduction activity (onset potential, 0.941 V; half wave potential, 0.830 V) and robust long-term durability in alkaline electrolyte. While in neutral condition, the MnBMP-based MWCNTs with Pd[P(Ph₃)₄] (PdMnN4/MWCNTs) are the most active heterobimetallic ORR catalyst and produce ultra-low concentration hydrogen peroxide (H₂O₂yield, 1.2%-1.3%). Synergistically tuning the ORR electrocatalytic activity and electron transfer pathway is achieved by the formation of NiBMP/MnBMP-Pd[P(Ph₃)₄] active sites. This work indicates such metalloporphyrin-Pd[P(Ph₃)₄] active sites on MWCNTs have significantly positive influence on electrocatalytic ORR systems and provides facile and mild strategy for designing highly efficient ORR electrocatalysts with ultra-low loading precious metal.

Keywords: heterobimetallic electrocatalyst; multi-walled carbon nanotubes; oxygen reduction; tetrakis(triphenylphosphine)palladium; transition metal porphyrin.