TY - JOUR
T1 - Steering palm oil hydrodeoxygenation towards biofuel production
T2 - An experimental and theoretical approach to unveil periodic trends
AU - Alkhoori, Sara Ishaq
AU - Al Areeqi, Seba
AU - Dabbawala, Aasif A.
AU - Siakavelas, Georgios
AU - Latsiou, Angeliki
AU - Anjum, Dalaver H.
AU - Harfouche, Messaoud
AU - Vasiliades, Michalis A.
AU - Hinder, Steven J.
AU - Baker, Mark A.
AU - Khaleel, Maryam
AU - Bahamon, Daniel
AU - Vega, Lourdes F.
AU - Goula, Maria A.
AU - Efstathiou, Angelos M.
AU - Polychronopoulou, Kyriaki
N1 - Publisher Copyright:
© 2024
PY - 2024/9
Y1 - 2024/9
N2 - The study presented herein examines the role of a series of alkaline earth metals (i.e. Mg, Ca, Sr, Ba) as promoters for Ni-supported zeolite beta catalysts to produce hydrocarbon fuels through hydrodeoxygenation (HDO) of palm oil. The properties of the catalytic systems were explored using XRD, HRTEM, N2 adsorption, H2-TPR, CO2-, NH3-, and H2-TPDs. The surface chemistry and coordination environment were analyzed using synchrotron XAFS and XPS. It is found that the chemical and structural composition of the support, as well as the use of alkaline earth promoters, significantly altered the interfacial charge distribution and consequently the electronic structure of the Ni-support interface and Ni surface sites. HDO of palm oil was conducted at 350 and 400 °C, at 30 bar; the highest conversion was attained over 10Ni/5Sr-Beta catalyst (44 %), which can be attributed to its features, such as low acidity (NH3-TPD/DRIFTS), high Ni dispersion (H2-TPD) and high amount of accessible Ni sites at reaction temperature (H2-TPR). Product analysis, in general, demonstrated higher selectivity towards bio-gasoline (C8–C14) as a result of high acidity of zeolite beta (Si/Al = 12.5) that promoted cracking activity. While the effect of alkaline earth metal cation promoters was investigated experimentally, DFT was utilized to investigate the trend on the deoxygenation of palmitic acid (predominant component of palm oil) over Ni(111) surface. Results revealed that although the elongated C−OH bond lengths, adsorption energies, and enhanced charge transfer between the −OH group and surface promoters can be linked to the periodicity of the adatom types, the thermodynamic –OH cleavage reaction energies well reflect the varying experimental deoxygenation performance of the Ni-promoted catalyst, ascribed to their varying C−O/promoter interactions subsequent to −OH cleavage.
AB - The study presented herein examines the role of a series of alkaline earth metals (i.e. Mg, Ca, Sr, Ba) as promoters for Ni-supported zeolite beta catalysts to produce hydrocarbon fuels through hydrodeoxygenation (HDO) of palm oil. The properties of the catalytic systems were explored using XRD, HRTEM, N2 adsorption, H2-TPR, CO2-, NH3-, and H2-TPDs. The surface chemistry and coordination environment were analyzed using synchrotron XAFS and XPS. It is found that the chemical and structural composition of the support, as well as the use of alkaline earth promoters, significantly altered the interfacial charge distribution and consequently the electronic structure of the Ni-support interface and Ni surface sites. HDO of palm oil was conducted at 350 and 400 °C, at 30 bar; the highest conversion was attained over 10Ni/5Sr-Beta catalyst (44 %), which can be attributed to its features, such as low acidity (NH3-TPD/DRIFTS), high Ni dispersion (H2-TPD) and high amount of accessible Ni sites at reaction temperature (H2-TPR). Product analysis, in general, demonstrated higher selectivity towards bio-gasoline (C8–C14) as a result of high acidity of zeolite beta (Si/Al = 12.5) that promoted cracking activity. While the effect of alkaline earth metal cation promoters was investigated experimentally, DFT was utilized to investigate the trend on the deoxygenation of palmitic acid (predominant component of palm oil) over Ni(111) surface. Results revealed that although the elongated C−OH bond lengths, adsorption energies, and enhanced charge transfer between the −OH group and surface promoters can be linked to the periodicity of the adatom types, the thermodynamic –OH cleavage reaction energies well reflect the varying experimental deoxygenation performance of the Ni-promoted catalyst, ascribed to their varying C−O/promoter interactions subsequent to −OH cleavage.
UR - http://www.scopus.com/inward/record.url?scp=85202292567&partnerID=8YFLogxK
U2 - 10.1016/j.mtchem.2024.102240
DO - 10.1016/j.mtchem.2024.102240
M3 - Article
AN - SCOPUS:85202292567
SN - 2468-5194
VL - 40
JO - Materials Today Chemistry
JF - Materials Today Chemistry
M1 - 102240
ER -