Scalable production of bifunctional ordered PtFe alloy electrocatalysts for efficient methanol oxidation and hydrogen evolution

Abstract

Ordered Pt-based alloys are highly promising for solving the problem of insufficient activity and stability of the methanol oxidation reaction (MOR) and the hydrogen evolution reaction (HER), while it is still challenging to synthesize them for large-scale commercial applications. To address these practical issues, herein we have simply developed a robust electrocatalyst named PtFe@HNC with ordered PtFe alloy nanoparticles supported on high nitrogen-content carbon (HNC). The PtFe@HNC electrocatalyst possesses abundant mesopores, sub-5 nm sized PtFe alloy nanoparticles and thin N-doped carbon (NC) shells, all of which are advantageous for the electrocatalytic activity and stability. The PtFe@HNC catalyst shows mass and specific activities of 1599.3 mA mg⁻¹ and 3.22 mA cm⁻² for the MOR, which are 5.35 and 6.08 times higher than those of commercial Pt/C, respectively. PtFe@HNC also presents a remarkable catalytic activity for the HER, with only a 15 mV overpotential to obtain 10 mA cm⁻² as well as a small Tafel slope of 12.5 mV dec⁻¹, which are superior to those of commercial Pt/C. PtFe@HNC also demonstrates robust catalytic durability toward both the MOR and HER during long-term operation. This work provides a simple and practical approach for scalable synthesis and insights into the operation of efficient Pt-based electrocatalysts for clean and renewable energy technologies.