Instituto de Electroquímica, Universidad de Alicante, Ap. 99, E-03080 Alicante, Spain.
J Chem Phys. 2019 Jan 28;150(4):041703. doi: 10.1063/1.5048489.
The catalytic effect of Pd on gold electrodes for glycerol oxidation is evaluated for Pd-Au surfaces prepared using three different methods: irreversible adsorption of palladium by a simple immersion of a gold electrode in palladium solution, the deposition of palladium on the gold substrate by a step potential from 1 to 0.75 V, and the forced deposition of palladium on the gold electrode with the help of a reducing hydrogen atmosphere. Voltammetry has been used for the electrochemical characterization of the Pd-Au deposits and to determine its reactivity towards glycerol oxidation, whereas FTIR experiments have allowed detecting adsorbed species and products formed during the oxidation reaction. Pd-Au surfaces prepared by irreversible adsorption are the electrodes that show the highest activity for the glycerol complete oxidation to carbonate, whereas Pd-Au surfaces made by the step potential are the catalyst that exhibits the highest rate for the formation and adsorption CO before carbonate production, poisoning the surface and diminishing their electrocatalytic properties. In addition to carbonate, glycerate, glycolate, and formate are detected as oxidation products. The integrated bands of the spectra are used to give quantitative information for comparing the product distribution of the different Pd-Au deposits prepared.
评估了 Pd 对金电极上甘油氧化的催化作用，用于制备 Pd-Au 表面的三种方法为：金电极简单浸入钯溶液中不可逆吸附钯、通过从 1V 到 0.75V 的阶跃电势在金基底上沉积钯、以及在氢气还原气氛帮助下强制在金电极上沉积钯。循环伏安法用于 Pd-Au 沉积物的电化学表征，并确定其对甘油氧化的反应性，而傅里叶变换红外（FTIR）实验则允许检测吸附物种和在氧化反应过程中形成的产物。通过不可逆吸附制备的 Pd-Au 表面是对甘油完全氧化为碳酸盐表现出最高活性的电极，而通过阶跃电势制备的 Pd-Au 表面则是在形成和吸附 CO 之前表现出最高速率的催化剂，CO 的形成和吸附会使表面中毒并降低其电催化性能。除了碳酸盐之外，还检测到甘油酸盐、乙醇酸盐和甲酸盐作为氧化产物。光谱的积分带用于提供定量信息，以比较不同制备的 Pd-Au 沉积物的产物分布。
