Structural and electrocatalytic characteristics of electrodeposited nickel-molybdenum alloys

摘要

The preparation of Ni-Mo alloys by electrodeposition from citrate baths was studied. The electrodeposition experiments were performed on rotating disk electrodes. The chemical composition of the Ni-Mo deposits was analyzed by energy dispersive X-ray spectroscopy. The structure of each sample was characterized by X-ray diffraction. It was found that the structure of the deposit varies with the molybdenum content in the deposit. The incorporation of molybdenum results in refinement of the nickel crystallite and expansion of the nickel lattice. Deposits with a Mo content of about 21 wt% or more exhibited an amorphous structure. The deposits obtained have been studied with the objective of qualitatively comparing and assessing their electrocatalytic activities as hydrogen evolution electrode in alkaline solutions. The electrocatalytic activity for hydrogen evolution increases with increasing Mo content. The size of the nickel crystallite also exerts certain effect on the Tafel slope of the hydrogen-evolution reaction. The electrocatalytic hydrogenation of 2-cyclohexen-1-one to cyclohexanone has also been investigated using the Ni-Mo deposits prepared. High selectivity and high current efficiency of the carbon-carbon double bond hydrogenation were observed with the Ni-Mo alloy containing 2 wt% Mo. [References: 25]