Acta Phys. -Chim. Sin. ›› 1992, Vol. 8 ›› Issue (01): 59-63.doi: 10.3866/PKU.WHXB19920112

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IN-SITU FTIR Studies on Adsorption and Oxidation of 1,2-Propanediol at a Platinum Electrode in Acid Solutions

Sun Shi-Gang; Yang Dong-Fang; Tian Zhao-Wu   

  1. State Key Laboratory for Physical Chemistry of the Solid Surface, Department of Chemistry, Xiamen University, Xiamen 361005
  • Received:1990-07-13 Revised:1991-03-11 Published:1992-02-15
  • Contact: Sun Shi-Gang

Abstract: Adsorption and oxidation of 1,2-propanediol at a platinum electrode in acid solutions were investigated by cyclic voltammetry and in-situ FTIR spectroscopy. The results demonstrated that 1,2-propanediol oxidized on Pt electrode via a dual path reaction mechanism. 1,2-propanediol may be oxidized into CO_2 through its disso-ciative products on Pt surface. But at lower potentials these dissociative products, which were mainly CO_(ad) and[﹥C=CH_2]_(ad) as detected by in situ-FTIR spectroscopy, may adsorb strongly and accumulate on electrode, empoisoning Pt electrode and suppressing consequently other reactions. However all dissociative products may be oxidized and desorbed from Pt surface when E>0.3 V, which reactivates Pt electrode and enables that 1,2-propanediol oxidizes via reactive intermediates into CO_2. The reactive intermediates were detected by in-situ FTIR spectroscopy under present conditions as OHC—CHOHCH_3 (or CH_2OH—COCH_3) and HOOC—COCH_3 (or HOOC—COCH_3) species.

Key words: 1,2-propanediol, Dissociative adsorption, Electrooxidation, in situ FTIR spectroscopy