Journal of Power Sources ( IF 8.1 ) Pub Date : 2017-09-06 , DOI: 10.1016/j.jpowsour.2017.08.089 Mohamed S.E. Houache , Emily Cossar , Spyridon Ntais , Elena A. Baranova
The Glycerol electrooxidation reaction (GEOR) was investigated on nickel electrode in alkaline media following a sinusoidal-wave treatment in a solution of 0.1 M Na2SO4 + 30 mM ascorbic acid. This treatment significantly increased the catalytic activity of Ni towards the GEOR. The electrochemical active surface area showed a six-fold increase, while the current density of glycerol oxidation was enhanced over nine times with a concurrent onset potential decrease by 45 mV. SEM analysis before and after the treatment revealed some morphology changes through the formation of additional grooves and pits on the Ni surface. XPS confirmed that before the treatment, the surface consists of Ni metal in addition to NiO, Ni(OH)2 and NiOOH, whereas after the treatment, 97% of the surface is Ni hydroxide composed of Ni2+ and Ni3+. Chronoamperommetry coupled with in-situ polarization modulation infrared-reflection absorption spectroscopy (PM-IRRAS) for simultaneous analysis of products on the Ni surface and in the bulk solution showed that the main reaction products on both untreated and treated Ni surfaces are glyceraldehyde, carbonyl, carboxylate ions and some carbon dioxide.
中文翻译:
镍表面的电化学修饰,可实现高效的甘油电氧化
在0.1 M Na 2 SO 4 + 30 mM抗坏血酸溶液中进行正弦波处理后,在碱性介质中的镍电极上研究了甘油电氧化反应(GEOR)。该处理显着提高了Ni对GEOR的催化活性。电化学活性表面积显示出六倍的增加,而甘油氧化的电流密度提高了九倍以上,同时起始电位降低了45 mV。处理前后的SEM分析表明,通过在镍表面上形成额外的凹槽和凹坑,一些形态发生了变化。XPS证实,在处理之前,表面除NiO和Ni(OH)2外还由Ni金属组成和NiOOH,而在处理后,表面的97%是由Ni 2+和Ni 3+组成的氢氧化镍。计时安培与原位偏振调制红外反射吸收光谱法(PM-IRRAS)结合使用,可同时分析Ni表面和本体溶液中的产物,表明未经处理和已处理的Ni表面上的主要反应产物均为甘油醛,羰基,羧酸根离子和一些二氧化碳。