In situ FTIR investigation of acetic acid electrooxidation on carbon supported Pt–Sn based trimetallic catalysts: Influence of the nature of the third metal

• Published in: Applied surface science 2014-12, Vol.321, p.426-431
• Main Authors: Beyhan, Seden, Léger, Jean-Michel, Kadırgan, Figen
• Format: Article
• Language: English
• Subjects: Acetates; Acetic acid; Acetic acid electrooxidation; Carbon dioxide; Carbonates; Catalysis; Catalysts; Chemical Sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; FTIR spectroscopy; Nickel; Palladium; Physics; PtSn-based trimetallic catalyst; Surface chemistry
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2014.10.051

•The effect of adding a third metal to PtSn/C for electrooxidation of acetic acid.•Formation of CO2 proceeds via acetyl or carbonate through surface acetate.•The beneficial role of adsorbed water for decomposition of acetate to carbonate.•A remarkable OH stretching band in the presence of Pd or Ni.•Surface charge effects on the water adsorption and acetyl decomposition. The effect of adding a third metal (Ni, Co, Pd, Rh) to Pt–Sn/C catalyst has been investigated for the adsorption and oxidation of acetic acid in acidic medium using in situ Fourier transform infrared (FTIR) spectroscopy. The results showed that the decomposition of acetic acid on the surface leads to the formation of different intermediate species and products such as acetate, acetyl, carbonate, CO and CO2. The reaction pathway of CO2 production proceeds via the formation of acetyl or carbonate through surface acetate species. It has been found that the selectivity of the acetate was enhanced by the addition of any third metal. However, the presence of Pd or Co increases the relative intensity of IR band for CO2. This is probably due to success in facilitating of the CC bond cleavage of acetyl. On the other hand, the conversion of acetate to carbonate is strongly affected by the adsorbed water, as is evident from the pronounced changes in the OH stretching region with the presence of Pd or Ni.