Ultralow Pt⁰ loading on MIL-88A(Fe) derived polyoxometalate-Fe₃O₄@C micro-rods with highly-efficient electrocatalytic hydrogen evolution

Abstract

Synthesis of catalysts with high activity for hydrogen evolution reaction (HER) has been a hot topic in electrocatalysis. In this paper, using MIL-88A(Fe) metal-organic complex, polyoxometalate (POM) and H₂PtCl₆ as starting materials, hierarchic and low Pt⁰-loading micro-rods (denoted as Pt-POMFe, i.e. Pt-PW₁₂Fe or Pt-PMo₁₂Fe) have been synthesized, in which the Pt⁰ nanoparticles can be stabilized by POM. The Pt-PW₁₂Fe micro-rod containing [PW₁₂O₄₀]^3- polyoxoanion component (0.30% Pt⁰-loading) which retains the spindle structure of its parent MIL-88A(Fe) exhibits a low overpotential of 28 mV at current density of 10 mA·cm⁻² for HER that is close to the electrocatalytic effect of commercial Pt/C (ca. 20% Pt⁰-loading). Such high electrocatalytic reactivity is mainly caused by the synergistic effect of the three components of POM, Pt⁰, and Fe₃O₄@C. The structure effectively increases the active sites of the catalyst and improves its conductivity and stability. The Pt-POMFe catalyst extends a new family of MOF-POM functional materials and provides a new concept to the design and synthesis of highly-efficient and low-cost electrocatalyst for hydrogen production.

Graphical Abstract

Keywords:

• Polyoxometalate
• hydrogen evolution reaction
• Pt nanoparticles
• metal-organic frameworks
• hierarchical

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

We gratefully acknowledge the financial support from the National Natural Science Foundation of China (21971085 and 51803074), the Natural Science Foundation of Shandong Province (ZR2017MEM003 and ZR2019MB004) and the Natural Science Foundation of Heilongjiang Province (B2017013).