Influence of the Oxide Content in the Catalytic Power of Raney Nickel in Hydrogen Generation

ABSTRACT

The influence of oxides in the hydrogen evolution on Raney nickel electrocatalysts was characterized by electrochemical impedance measurements. In addition, these materials show competitive overpotentials for hydrogen evolution with a modified Watts bath as a binder for the Raney nickel. The optimum result was −190 mV of overpotential at 100 mA cm⁻². Oxygen in the Raney Ni catalyst affects its electroactivity toward hydrogen evolution. The source of oxygen is related to the presence of chloride ions in the modified Watts bath. A Watts bath binds Raney Ni particles to the surface of the catalysts and chloride regulates the oxygen content in the nickel binder during electrodeposition. High oxygen content increases the hydrogen evolution overpotential of the electrode. The electroactivity of the synthesized porous coatings was evaluated by polarization curves and impedance plots. In addition, surface characterization by X-ray diffraction, field emission–scanning electron microscopy equipped with energy-dispersive analysis, and X-ray photoelectron spectroscopy is reported.

KEYWORDS:

• Electrochemical impedance spectroscopy (EIS)
• energy-dispersive spectroscopy (EDS)
• field emission–scanning electron microscopy (FE-SEM)
• hydrogen evolution reaction (HER)
• X-ray diffraction (XRD)
• X-ray photoelectron spectroscopy (XPS)

Acknowledgments

We want to acknowledge the Global R&D Centers Program of NRF (National Research Foundation of Korea), funded by MSIP (Ministry of Science, ICT & Future Planning) at KIGAM (Korean Institute of Geoscience and Mineral Resources) for instrument time. The authors would like to thank AINSE for providing financial assistance (Award No ALNGRA12020/10366 and AINSE Post Graduate Research Award 10595) to enable work on catalyst surfaces. We would also like to acknowledge the technological support from ANSTO (Australian Nuclear Science and Technology Organization).

Additional information

Funding

This work was supported by the Australian Institute of Nuclear Science and Engineering [Grant Number 10595,ALNGRA12012/10366], National Research Foundation of Korea [Grant Number 2011-00123], and AINSE for [Grant Number Award No ALNGRA12020/10366 and AINSE Post Graduate Research Award 10595]