Electrospun Co Nanoparticles@PVDF-HFP Nanofibers as Efficient Catalyst for Dehydrogenation of Sodium Borohydride

Abstract

Metallic Co NPs@poly(vinylidene fluoride-co- hexafluoropropylene) nanofibers (PVFH NFs) were successfully synthesized with the help of electrospinning and in situ reduction of Co2+ ions onto the surface of PVFH membrane. Synthesis of PVFH NFs containing 10, 20, 30, and 40 wt% of cobalt acetate tetrahydrate was achieved. Physiochemical techniques were used to confirm the formation of metallic Co@PVFH NFs. High catalytic activity of Co@PVFH NFs in the dehydrogenation sodium borohydride (SBH) was demonstrated. The formulation with 40 wt% Co proved to have the greatest performance in comparison to the others. Using 1 mmol of SBH and 100 mg of Co@PVFH NFs, 110 mL of H2 was produced in 19 min at a temperature of 25 °C, but only 56, 73, and 89 mL were produced using 10, 20, and 30 wt% Co, respectively. With the rise of catalyst concentration and reaction temperature, the amount of hydrogen generated increased. By raising the temperature from 25 to 55 °C, the activation energy was lowered to be 35.21 kJ mol−1 and the yield of H2 generation was raised to 100% in only 6 min. The kinetic study demonstrated that the reaction was pseudo-first order in terms of the amount of catalyst utilized and pseudo-zero order in terms of the SBH concentration. In addition, after six cycles of hydrolysis, the catalyst showed outstanding stability. The suggested catalyst has potential applications in H2 generation through hydrolysis of sodium borohydride due to its high catalytic activity and flexibility of recycling.