Herein we investigate the effect of irreversibly adsorbed bismuth on polycrystalline platinum (Ptp) on the electrooxidation of glycerol in alkaline media by combining electrochemical, spectroscopic (in situ FTIR), and analytical (HPLC on line) techniques. We found that the activity of Ptp increases by about 5-fold when the optimal quantity of Bi ions is added to the solution. Besides, the adatom strongly impacts the reaction products by suppressing the pathways with C-C bond breaking, hindering the formation of CO (and other unknown intermediates) and enhancing the production of glycerate. Different from the results in acid media for Ptp-Bi systems where Bi blocks the oxidation pathway through the primary carbon, glycerate is the main product in alkaline media, and dihydroxyacetone is either produced in extremely low quantities or not produced. Besides, comparing our results with those in acid media, the peak current recorded at 1 mV·s-1 in this work was 1 order of magnitude higher. These results show the strong impact of the pH in the reaction rate and selectivity.
De Souza M.B.C., Vicente R.A., Yukuhiro V.Y., Pires C.T.G., Cheuquepan W., Bott-Neto J.L., et al. (2019). Bi-modified Pt Electrodes toward Glycerol Electrooxidation in Alkaline Solution: Effects on Activity and Selectivity. ACS CATALYSIS, 9(6), 5104-5110 [10.1021/acscatal.9b00190].
Bi-modified Pt Electrodes toward Glycerol Electrooxidation in Alkaline Solution: Effects on Activity and Selectivity
Pires C. T. G.;
2019
Abstract
Herein we investigate the effect of irreversibly adsorbed bismuth on polycrystalline platinum (Ptp) on the electrooxidation of glycerol in alkaline media by combining electrochemical, spectroscopic (in situ FTIR), and analytical (HPLC on line) techniques. We found that the activity of Ptp increases by about 5-fold when the optimal quantity of Bi ions is added to the solution. Besides, the adatom strongly impacts the reaction products by suppressing the pathways with C-C bond breaking, hindering the formation of CO (and other unknown intermediates) and enhancing the production of glycerate. Different from the results in acid media for Ptp-Bi systems where Bi blocks the oxidation pathway through the primary carbon, glycerate is the main product in alkaline media, and dihydroxyacetone is either produced in extremely low quantities or not produced. Besides, comparing our results with those in acid media, the peak current recorded at 1 mV·s-1 in this work was 1 order of magnitude higher. These results show the strong impact of the pH in the reaction rate and selectivity.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
