TY - JOUR
T1 - Effect of different solvents on hydrogen production from hydrolysis of potassium borohydride with a new and active Ni-based catalyst synthesized by green synthesis
AU - Şahin, Ömer
AU - Ekinci, Selma
AU - İzgi, Mehmet Sait
AU - Onat, Erhan
N1 - Publisher Copyright:
© 2024 Hydrogen Energy Publications LLC
PY - 2025
Y1 - 2025
N2 - In this study, a novel Ni-based catalyst supported on carbon quantum dots (CQDs), synthesized from caffeine via a green hydrothermal method was developed to enhance hydrogen generation. The effects of different solvents, including water, and ethanol, on the catalyst's performance were explored. The results demonstrate that the Ni@CQDs catalyst prepared in ethanol exhibited superior hydrogen production rates due to improved nickel dispersion and higher surface area, as confirmed by BET, XPS, and XRD analyses. Ethanol was found to effectively modify the catalyst, resulting in faster H₂ conversion compared to water. The HGR values obtained with catalysts synthesized in water and ethanol were 4662, and 12262 mL min−1g−1, respectively. The study also investigated the impact of KOH concentration, catalyst loading, KBH4 concentration, and temperature on the hydrolysis process. The Ni@CQDs catalyst synthesized in ethanol achieved optimal performance at higher KBH₄ and KOH concentrations, producing 100% H2 yield over six reusability cycles with minimal loss of catalytic efficiency. Thermodynamic analysis using the Arrhenius and Eyring-Polanyi equations indicated that the catalyst in ethanol had a lower activation energy, enhancing the hydrolysis reaction rate. The Ni@CQDs (ethanol) catalyst exhibited a significantly higher TOF of 1696 h⁻1 at 4% KBH4 concentration and a lower activation energy (Ea) of 33.78 kJ mol−1 compared to the Ni@CQDs (water) catalyst, which had a TOF of 601.5 h⁻1 at 2% KBH4 concentration and an Ea of 38.93 kJ mol−1, indicating superior catalytic efficiency with ethanol as the solvent.
AB - In this study, a novel Ni-based catalyst supported on carbon quantum dots (CQDs), synthesized from caffeine via a green hydrothermal method was developed to enhance hydrogen generation. The effects of different solvents, including water, and ethanol, on the catalyst's performance were explored. The results demonstrate that the Ni@CQDs catalyst prepared in ethanol exhibited superior hydrogen production rates due to improved nickel dispersion and higher surface area, as confirmed by BET, XPS, and XRD analyses. Ethanol was found to effectively modify the catalyst, resulting in faster H₂ conversion compared to water. The HGR values obtained with catalysts synthesized in water and ethanol were 4662, and 12262 mL min−1g−1, respectively. The study also investigated the impact of KOH concentration, catalyst loading, KBH4 concentration, and temperature on the hydrolysis process. The Ni@CQDs catalyst synthesized in ethanol achieved optimal performance at higher KBH₄ and KOH concentrations, producing 100% H2 yield over six reusability cycles with minimal loss of catalytic efficiency. Thermodynamic analysis using the Arrhenius and Eyring-Polanyi equations indicated that the catalyst in ethanol had a lower activation energy, enhancing the hydrolysis reaction rate. The Ni@CQDs (ethanol) catalyst exhibited a significantly higher TOF of 1696 h⁻1 at 4% KBH4 concentration and a lower activation energy (Ea) of 33.78 kJ mol−1 compared to the Ni@CQDs (water) catalyst, which had a TOF of 601.5 h⁻1 at 2% KBH4 concentration and an Ea of 38.93 kJ mol−1, indicating superior catalytic efficiency with ethanol as the solvent.
KW - Carbon quantum dots
KW - Green synthesis
KW - Hydrogen
KW - Potassium borohydride
UR - http://www.scopus.com/inward/record.url?scp=85213978650&partnerID=8YFLogxK
U2 - 10.1016/j.ijhydene.2024.12.443
DO - 10.1016/j.ijhydene.2024.12.443
M3 - Article
AN - SCOPUS:85213978650
SN - 0360-3199
JO - International Journal of Hydrogen Energy
JF - International Journal of Hydrogen Energy
ER -