Effect of peptide aerogel composite on silver nanoparticles as a catalyst for electrochemical CO₂ reduction

Abstract

Electrochemical reduction of carbon dioxide (CO₂RR) product distribution has been found to be dependent on several key factors, such as catalyst surface morphology, stability, and porosity. Metal-modified carbon-based materials have received a lot of attention in CO₂RR. However, designing a highly active metal carbon catalyst for CO₂RR utilizing low-cost chemical precursors remains a challenge. Here, a series of myristic acid-Phe-Phe peptide (MA-FF) aerogel materials containing graphene oxide (Gox) and Ag nanoparticles have been prepared for electrochemical CO₂RR. The morphologies of the composites were studied by scanning electron microscopy (SEM), and their surface compositions were determined using X-ray photoelectron spectroscopy (XPS). While the peptide aerogel alone showed no catalytic activity for CO₂ electroreduction, the addition of Ag nanoparticles results in a Faradaic efficiency (FE) of 46% for electroreduction of CO₂ to CO at an overpotential of − 0.8 V vs. RHE. Incorporation of Gox in the aerogel increases the FE to 88% and allows CO₂ reduction at a lower overpotential of − 0.7 V vs. RHE. Using highly porous peptide aerogels-Gox in addition to the metal active center provides an enhanced and new method for CO₂ conversion using low environmental impact bio-based aerogels.