Hydrogen generation from methanolysis of sodium borohydride using boric acid as a catalyst

ABSTRACT

Hydrogen plays a critical role in reducing dependence on fossil fuels and combating climate change as a clean, highly efficient, and renewable energy source. In this study, hydrogen production via methanolysis of sodium borohydride (NaBH₄) has been investigated in the presence of boric acid (H₃BO₃) catalyst. The effect of various parameters on hydrogen generation rate has been reported and the effect of temperature, H₃BO₃ catalyst concentration, methanol volume and NaBH₄ concentration has been studied in the range of 20–50°C, 0.539–2.695 mM, 2–20 mL, and 0.176–0.881 mM, respectively. The kinetic parameters are estimated with the power law model and the reaction order and activation energy are found as 2 and 33.25 kJ·mol⁻¹, respectively. The highest hydrogen generation rate (HGR) is achieved as 628,117 mL·min⁻¹·g cat⁻¹ at 50°C with 1.078 mM H₃BO₃ and 0.352 M NaBH₄ concentrations and 15 mL methanol volume. This study’s notable result is the emphasis on the effect of using a very small amount of boric acid. Because the use of a high amount of boric acid as a catalyst causes steric hindrance in the methanolysis reaction of trimethyl borate, which is the product of the equilibrium reaction between boric acid and excess alcohol in the solution. This situation has been avoided by using a lower amount of boric acid. Thus, it demonstrates that environmentally friendly, efficient, and cost-effective boric acid has great potential in hydrogen production via methanolysis and that its performance can be further improved with more work on the optimization of catalyst concentration.

KEYWORDS:

• Hydrogen production
• methanolysis
• sodium borohydride
• catalysis
• boric acid

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Additional information

Funding

The author reported there is no funding associated with the work featured in this article.

Notes on contributors

M. Bora Akin

Muhammed Bora Akin works as Assistant Professor in the Department of Chemical Engineering at Çankırı Karatekin University. He graduated his MSc in 2005 from the Faculty of Chemical and Metallurgical Engineering at Yıldız Technical University. He has also completed PhD education at 2011 from Yıldız Technical University.