Role of alkali and alkaline-earth doped in zeolite A-derived from industrial waste toward direct ethanol dehydrogenation to acetaldehyde

Authors

• Darunee Sukchit
• Malee Prajuabsuk
• Chan Inntam
• Saisamorn Lumlong
• Bongkochawan Pakamwong
• Auradee Punkvang
• Duangkamol Gleeson
• Pantita Trongjitraksa
• Paramasivam Shanmugam
• Supakorn Boonyuen
• Niramol Juntarachat
• Sasijuta Wattanarach
• Parjaree Thavorniti
• Bunjerd Jongsomjit
• Pornpan Pungpo

Publication Date

2026

Abstract

In this study, a sustainable catalytic route for converting ethanol into value-added acetaldehyde was developed using alkali- and alkaline earth-modified zeolite A synthesized from sugarcane bagasse ash (SCBA). Zeolite A was first prepared via alkaline fusion followed by hydrothermal crystallization and subsequently doped with 1 wt% K+ or Ca2+ using incipient wetness impregnation. Comprehensive physicochemical characterization (X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), Fourier transform infrared spectroscopy (FTIR), nitrogen physisorption (N2 physisorption), ammonia temperature-programmed desorption (NH3-TPD), and carbon dioxide temperature-programmed desorption (CO2-TPD)) confirmed the formation of a highly crystalline LTA framework with tunable acid-base properties upon cation incorporation. Catalytic evaluation demonstrated that ethanol dehydrogenation strongly depends on the balance of surface acid-base sites. The parent and Ca-modified zeolite A exhibited moderate acetaldehyde selectivity (11.2% and 21.2%, respectively), likely due to competing dehydration reactions. In contrast, K-modified zeolite A achieved higher acetaldehyde selectivity (51.8%) at 35.2% ethanol conversion, attributed to enhanced surface basicity and suppressed acidity. Mechanistic analysis suggests that K+ and Ca2+ promote ethanol dehydrogenation by facilitating ethoxide formation and β-hydrogen elimination on basic lattice oxygen sites. These findings demonstrate a cost-effective, noble-metal-free catalytic strategy and highlight the potential of SCBA-derived zeolite A as a sustainable platform for green ethanol upgrading.

DOI

10.55713/jmmm.v36i3.2647

First Page

1

Last Page

15

Recommended Citation

Sukchit, Darunee; Prajuabsuk, Malee; Inntam, Chan; Lumlong, Saisamorn; Pakamwong, Bongkochawan; Punkvang, Auradee; Gleeson, Duangkamol; Trongjitraksa, Pantita; Shanmugam, Paramasivam; Boonyuen, Supakorn; Juntarachat, Niramol; Wattanarach, Sasijuta; Thavorniti, Parjaree; Jongsomjit, Bunjerd; and Pungpo, Pornpan (2026) "Role of alkali and alkaline-earth doped in zeolite A-derived from industrial waste toward direct ethanol dehydrogenation to acetaldehyde," Journal of Metals, Materials and Minerals: Vol. 36: No. 3, Article 3.
DOI: 10.55713/jmmm.v36i3.2647
Available at: https://digital.car.chula.ac.th/jmmm/vol36/iss3/3