Simultaneous Formation of a Tensile-Strained PtNiBi Shell/Intermetallic PtBi Core for Self-Powered Methanol Upgrading and Hydrogen Production.

Methanol oxidation is vital for direct methanol fuel cells (DMFCs) and energy-saving H2 production by replacing the sluggish oxygen evolution reaction, but it suffers from CO poisoning, CO2 emission, and high overpotential issues. Herein, we present the simultaneous formation of a monodispersed intermetallic PtBi core/tensile-strained PtNiBi shell (I-PtBi@TS-PtNiBi) via a one-pot wet chemical method, to facilitate a self-powered methanol upgrading and H2 production system without CO2 emission. This I-PtBi@TS-PtNiBi electrocatalyst exhibits a high mass activity of 33.2 A mg-1 Pt toward methanol oxidation and produces value-added formate with high Faradaic efficiencies over a wide potential window of 0.6 to 1.2 V. This enables a high DMFC peak power density of 175.0 mW cm-2 to drive efficient H2 production in an anion-exchange-membrane water electrolyzer at low cell voltages (1.16 V@2.0 A cm-2), producing formate in both the DMFC and electrolyzer. This work offers insights into the rational design and synthesis of sophisticated multimetallic electrocatalysts for efficient energy conversion and chemical upgraders.