Pt Atomic Site-Engineered Redox Mediator Boosts Electrosynthesis of Formic Acid from Glycerol

Area of Science:

• Electrochemistry
• Catalysis
• Materials Science

Background:

• Electrosynthesis of formic acid from glycerol typically uses Ni-based catalysts with dual mediators (Ni³⁺-O and Ni²⁺δ-(OH)ads).
• The high potential required for Ni³⁺-O limits the overall efficiency and energy consumption of this process.

Purpose of the Study:

• To develop a novel catalytic system for efficient formic acid electrosynthesis from glycerol at significantly lower potentials.
• To overcome the limitations imposed by the dual-mediator mechanism in existing Ni-based catalysts.

Main Methods:

• Engineering platinum (Pt) atomic sites onto Ni aerogels to create modified Ni²⁺δ-(OH)ads redox mediators.
• Investigating the catalytic performance of Pt-engineered Ni catalysts for glycerol electrooxidation.
• Analyzing the reaction mechanism, focusing on C-C bond cleavage and hydrogen atom transfer.

Main Results:

• The Pt-engineered Ni catalyst (Ni₉₃Pt₇) achieved a low onset potential of 1.25 V, outperforming unmodified Ni aerogels (1.36 V).
• Demonstrated high efficiency (250 C) for complete glycerol conversion with excellent stability (>180 h).
• Circumvented the high-potential Ni³⁺-O pathway, favoring the Ni²⁺δ-(OH)ads mediator.

Conclusions:

• Pt atomic site engineering on Ni catalysts provides an effective strategy to bypass limitations of dual-mediator systems.
• This approach enables highly efficient and low-potential electrosynthesis of formic acid from glycerol.
• The methodology shows broad applicability for low-carbon compound synthesis from vicinal polyols.