Investigation of High-Activity Activated Carbon-Supported Co-Cr-B Catalyst in the Generation of Hydrogen from Hydrolysis of Sodium Borohydride

Orhan Baytar

doi:10.17344/acsi.2017.4151

Abstract

In this study, activated carbon-supported Co-Cr-B catalyst was synthesized by chemical impregnation and precipitation method for use in the catalytic hydrolysis of sodium borohydride (NaBH4). The activity of Co-Cr-B / activated carbon (5-20%) obtained by using different ratios was investigated while synthesizing activated carbon-supported Co-Cr-B catalyst. The effects of some parameters such as NaOH Concentration (0-5%), NaBH4 concentration (2.5-10%), amount of catalyst (25-100 mg) and solution ambient temperature were investigated in the catalytic hydrolysis of NaBH4. The hydrogen production rate of Co-Cr-B catalyst without support in hydrolysis of NaBH4 was found as 6.5 Lg-1 min-1 catalyst while the hydrogen production rate of activated carbon supported Co-Cr-B catalyst was found as 30.2 Lg-1 min-1 catalyst. In presence of activated carbon-supported Co-Cr-B catalyst, the hdyrolysis kinetic order and activation energy of NaBH4 were found as 0.126 and 16.27 kJ/mol, respectively. The results suggest that activated carbon-supported Co-Cr-B catalysts can be used for mobile applications of Proton exchange membrane fuel cell (PEMFCs) systems.

Highlights

Depletion of existing fossil fuels, global warming and environmental pollution are increasing demands for a clean and sustainable energy system.[1]
The structure properties of activated carbon, activated carbon supported Co-Cr-B catalyst (15% Co-Cr-B loaded) and Co-Cr-B catalyst were determined by XRD and the obtained results are displayed in Figure 3a, Figure 3b and Figure 3c, respectively
In this study, activated carbon supported Co-Cr-B catalyst was prepared to use in the hydrolysis of NaBH4

Summary

Introduction

Depletion of existing fossil fuels, global warming and environmental pollution are increasing demands for a clean and sustainable energy system.[1]. An aqueous solution of metal hydride stabilized can be considered as a suitable material for hydrogen storage.[3] Metal hydrides are compounds such as NaBH4, NaH, CaH2, MgH2, LiAlH2 Among these metal hydrides, NaBH4 has some advantages such as high hydrogen storage capacity (10.8%), high stability and non-flammability at high pH, optimum control over the rate of hydrogen production with supported catalysts, acceptable hydrogen production rate even at low temperatures, ease of use and availability.[4,5] The hydrolysis of NaBH4 with water is indicated the following reaction.[6]. In our previous study, activated carbon was synthesized from the elaeagnus seed by physical activation method using a mixture of CO2 and water vapor In this current study, the synthesized activated carbon was used as support material for the Co-Cr-B catalyst to be used for the hydrolysis of sodium borohydride.[18] The experimental conditions for the NaBH4 hydrolysis of the synthesized activated carbon supported Co-Cr-B catalyst were optimized. It was found that the activated carbon-supported Co-Cr-B catalyst has high activity in the hydrolysis of NaBH4

Experimental Part

Results and Discussions

Conclusions