Hydrogen Evolution and Benzyl Alcohol Oxidation on Ni-Mo Codeposit and Its Corrosion Behavior

• Main Authors: Cheng-Hui Lin, 林政輝
• Other Authors: Ten-Chin Wen
• Format: Others
• Language: zh-TW
• Published: 1994
• Online Access: http://ndltd.ncl.edu.tw/handle/97424652167023067090

碩士 === 國立成功大學 === 化學工程研究所 === 82 === The purposes of this thesis are intenteded to investigate the effects of various Ni-Mo codeposits (prepared by electroplating) on the performance of hydrogen evolution reaction (HER),corrosion inhibition and benzyl alcohol oxidation. The physical and electrochemical properties of Ni-Mo deposits are majorly influenced by electroplating solution pHs and species used for adjusting electroplating solution pH. Gradual change in preferred orientation for Ni-Mo crystalline growth from Ni<111> to Ni<200>, gradual increase in NiO and MoO3 within the Ni-Mo deposits, and gradual increase in rate for HER were simultaneous- ly found when pH values of electroplating solutions increased. The passive currents of Ni- Mo codeposits increase with increa sing Mo content within the codeposits in 1N HCl,1N H2SO4 and 0.1N NaCl . In 1N HNO3, no passive but direct pitting phenomenon was observed. The electrochemically active surface area (EASA for Ni(OH)2 / NiOOH transition) and limiting current for benzyl alcohol oxidat- ion on Ni-Mo codeposits are much larger than those on a pure Ni in basic solutions. Increase in EASA and limiting current for be- nzyl alcohol oxidation and decrease in oxygen evolution rate were observed as Mo content in codeposits increased. High initialy concentration of benzyl alcohol, high temperat- ure of electrolyte solution, low current density, and no addition of tert-butanol result in a high selectivity and current efficie- ncy for benzyl aldehyde production and benzyl alcohol oxidation, respectively. In 0.5N KOH with 0.6M benzyl alcohol at 60℃, 81.85 % selectivity for benzyl aldehyde and approximately 100% current efficiency for benzyl alcohol oxidation were obtained under 5 mA/cm2.