Correlations between experiments and simulations for formic acid oxidation

Area of Science:

• Electrochemistry
• Catalysis
• Renewable Energy

Background:

• Formic acid oxidation and CO2 reduction are crucial for closed carbon-loop systems powered by renewable energy.
• Formic acid fuel cells are limited by site-blocking species formed during formic acid oxidation.
• Understanding CO2 reduction mechanisms provides insights into the reverse reaction: formic acid oxidation.

Purpose of the Study:

• To investigate the mechanism and catalytic limitations of formic acid oxidation.
• To correlate simulation data with experimental results on various electrocatalysts.
• To identify the fundamental factors limiting formic acid oxidation efficiency.

Main Methods:

• Computational simulations on multiple materials.
• Experimental electrocatalytic oxidation of formic acid.
• Correlation of binding energetics and reaction pathways.

Main Results:

• Formate intermediate exhibits similar binding energetics on Pt, Pd, and Ag catalysts.
• Silver (Ag) was found to be ineffective as a catalyst for this reaction.
• Adsorbed hydrogen (*H) on catalyst surfaces promotes *CO formation and poisoning via disproportionation.

Conclusions:

• The binding energetics of formate do not solely determine catalytic activity.
• *H adsorption is a critical step leading to catalyst poisoning.
• Identifying these limitations advances the understanding of formic acid oxidation mechanisms for improved fuel cell performance.