Related Experiment Video
Updated: Jan 17, 2026

A Simple, Low-cost, and Robust System to Measure the Volume of Hydrogen Evolved by Chemical Reactions with Aqueous Solutions
Published on: August 17, 2016
Hydrogen generation from NaBH4 solutions using a molecular mixed-valence nickel-substituted
Yasemin Torlak1, Ebru Halvacı2, Bilge Akkoyun2
1Pamukkale University, Cal Vocational High School, Department of Agricultural and Livestock Production Cal Denizli 20700 Türkiye ytorlak@pau.edu.tr.
None:
In the exploration for clean and sustainable energy, hydrogen has emerged as an important alternative energy carrier. In this study, K7[NiIIINiII(H2O)W111O39]·15H2O (Ni-POM), a Keggin-type mixed valence polyoxometalate (POM) compound, was synthesised, and its catalytic effect on hydrogen production by hydrolysis of NaBH4 was investigated. The Ni-POM complex was characterised by UV-visible spectroscopy (UV-vis), FT-IR spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), cyclic voltammetry (CV) and atomic force microscopy (AFM) methods. The characteristic absorption band observed at 265 nm in the UV-vis was attributed to ligand-metal charge transfer originating from the Ni(iii) centres. XRD analyses confirmed the presence of a highly crystalline Keggin-type structure. TEM images identified its nanosized morphology dispersed in the range of 5-15 nm. The effects of temperature, substrate and catalyst concentrations were determined, which gave highhydrogen production rate, a conversion frequency (TOF) of 806.38 s-1 and an activation energy (E a) of 22.26 kJ mol-1 at the optimum conditions for the Ni-POM catalytic activity studies. Results showed that Ni-POM is a stable and promising homogeneous catalyst capable of showing high catalytic activity in hydrogen production via hydrolysis of NaBH4. The findings suggest that mixed-valence POMs may open opportunities for innovative applications in hydrogen energy technologies.
More Related Videos
Related Concept Videos
Catalysis
Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation reactions,...
Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
Reduction of Alkenes: Catalytic Hydrogenation
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
Aldehydes and Ketones to Alkanes: Wolff–Kishner Reduction
Alcohols from Carbonyl Compounds: Reduction
Catalytic hydrogenation is similar to the reduction of an alkene or alkyne by adding H2 across the pi bond in the presence of transition metal catalysts like Raney Ni, Pd–C, Pt, or Ru. Aldehydes and ketones can be reduced by this method, often under mild to moderate heat (25–100°C) and...

