Green Synthesis of Co-based Nanoparticles from Bean Shell Extract and Determination of the Effect of Their Activity on Sodium Borohydride Hydrolysis

Abstract

Abstract The study investigated the effect of Co(0) and Co-B NPs catalysts synthesized using the method of green synthesis on the NaBH4 hydrolysis process. The investigation of the structure and surface morphology of the catalysts was evaluated using XRD, SEM-EDX, TEM, FTIR, and XPS analyses. The effect of catalysts on NaBH4 was examined at different catalyst amounts, different NaBH4/NaOH concentrations, and different temperature values. At 30 °C solution temperature, the highest HGR and TOF values for Co(0) NPs catalyst were determined as 7326 mL.min-1.g-1cat and 8572 mL.min-1.g-1cat, respectively. Under the same conditions, HGR and TOF values for Co-B NPs catalyst were determined as 12524 mL.min-1.g-1cat and 15189 mL.min-1.g-1cat, respectively. The calculated activation energies for Co(0) and Co-B NPs catalysts are 37.68 kJmol-1 and 21.28 kJmol-1, respectively. Enthalpy and entropy values were calculated as 4.43 kJmol-1 and 44 Jmol-1K-1 for Co(0) and 23.16 kJmol-1 and 98 Jmol-1K-1 for Co-B NPs, using Eyring's equation, respectively. The catalysts showed a small decrease in activity over five cycles, indicating that they have potential for reusability.