Hydrogen generation from NaBH4 hydrolysis catalyzed by cobalt (0)-Deposited cross-linked polymer brushes: Optimization with an experimental design approach

• Published in: International journal of hydrogen energy 2023-04, Vol.48 (34), p.12814-12825
• Main Authors: Ecer, Ümit, Zengin, Adem, Şahan, Tekin
• Format: Article
• Language: English
• Subjects: Cobalt; Gel-brush; Hydrogen generation; NaBH4 hydrolysis; Pumice; Response surface methodology
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2022.12.224

Proposing a novel catalyst that achieves catalytic hydrolysis of metal hydrides is an important stage in developing a hydrogen storage system. In this study, a cross-linked gel brush-cobalt (0) composite (Co@P4VPGB@PMC) has been synthesized to obtain hydrogen from NaBH4 solution. The morphology, structure, and composition of the obtained catalyst have been characterized by, FTIR, SEM, EDX, BET, XRD, ICP-MS and XPS. The parameters that significantly affect the hydrolysis of NaBH4 (such as NaBH4 concentration, NaOH amount, catalyst amount, and temperature) have been investigated using response surface methodology (RSM), an optimization method that has gained increasing importance in recent years. The hydrogen generation rate (HGR) was 4499 mL/min gcat for Co@P4VPGB@PMC when the NaBH4 amount was 241.52 mM, NaOH amount 5 wt%, catalyst amount 10.55 mg and temperature 58.9 °C. Moreover, the apparent activation energy (Ea) for the catalytic hydrolysis reaction has been 41.27 kJmol-1 obtained under optimum conditions. Additionally, the Co@P4VPGB@PMC catalyst displayed significant reusability performance for up to five cycles without major loss of its activity. Compared with metal catalysts, this new cross-linked polymer gel brush-cobalt catalyst has excellent potential applications for hydrogen production by hydrolysis of metal hydrides due to its simple synthesis, low cost, and the easy availability of raw materials. [Display omitted] •Cross-linked gel brush-cobalt composite was synthesized successfully.•RSM-based model for optimization of the hydrolysis reaction is improved.•Maximum HGR was measured to be 4499 mL/min. gcat at optimum conditions.•Promising Ea was obtained when compared with the Co-based catalysts.•The catalyst indicates the excellent catalytic activity and stability.