Hydrogen evolution on plasma carburised nickel and effect of iron deposition from electrolyte in alkaline water electrolysis

Date

2015

Advisors

Journal Title

Journal ISSN

ISSN

Volume Title

Publisher

Elsevier

Type

Article

Peer reviewed

Yes

Abstract

Presence of carbon in electrodeposited nanocrystalline Ni-Fe-C cathodes renders a high electroactivity for hydrogen evolution reaction (HER) in hot alkaline solutions. In the present work carbon was introduced into nickel cathodes by plasma treatment in CH4 + H2 gas mixture at 47 0 C. Electrochemical measurements were carried out in the solution of 25 wt.% KO H (reagent p.a.) at 80 C. In some measurements the solution wa s pre-electrolysed to remove heavy metals. Carburisation resulted in a significant enhancement of catalytic activity of nickel for HER during short cathodic polarisation. Later, differences between the materials almost disappeared, evidently due to deposition of iron and of other heavy metals from the solution. Cathodes with iron deposits underwent an activation following anodic polarisation. It wa s proposed that the activating effect of iron can be associated with the formation of highly reactive iron during cathodic reduction of oxide species (probably Fe(OH)4 2 ). The activating effect of prior anodic polarisation can be due to the formation of large amounts of oxide species which can undergo the reduction to reactive iron.

Description

Keywords

Electrolysis, Carburised nickel, Anodic activation, Iron deposition

Citation

Flis-Kabulska, I. et al. (2015) Hydrogen evolution on plasma carburised nickel and effect of iron deposition from electrolyte in alkaline water electrolysis. Electrochemica Acta, 167, pp. 61-68

Rights

Research Institute

Institute of Engineering Sciences (IES)