Chulalongkorn University Theses and Dissertations (Chula ETD)
Hydrogen discharging and recharging of NaAIH0subscript 4] and HfCI[subscript 4]-NaAIH
Other Title (Parallel Title in Other Language of ETD)
กระบวนการปล่อยและเก็บไฮโดรเจนของโซเดียมอะลาเนทและโซเดียมอะลาเนทที่เติมฮอฟเนียม (IV) คลอไรด์
Year (A.D.)
2006
Document Type
Thesis
First Advisor
Pramoch Rangsunvigit
Faculty/College
Faculty of Science (คณะวิทยาศาสตร์)
Degree Name
Master of Science
Degree Level
Master's Degree
Degree Discipline
Chemistry
DOI
10.58837/CHULA.THE.2006.1139
Abstract
Mechanisms of hydrogen desorption and absorption were investigated by the X-ray diffraction technique. NaH and AIH which play a major role in both dehydrogenation and rehydrogenation, were found. In addition, HfH | O,x2<, can be observed in XRD patterns of the doped NaAIH . Attempts were also made to reduce the formation of Hf-AI alloys during the hydrogen desorption/absorption of HfCI-NaAIH by adding a chelating complex (H PP or HfCI TPP) as a co-catalyst. The desorption temperature of HfCI-NaAIH doped with the co-catalyst is lower (75 C) than that of the undoped co-catalyst one (90 C). Moreover, there was no Hf-AI alloys detected. However, the amount of reabsorbed hydrogen in subsequent cycles reduced because of the incomplete rehydrogenation from Na AIH to NaAIH. When using CuCrO as another co-catalyst, the hydrogen desorption took place at the temperature range of 62-270 C. The temperature of the first hydrogen desorption decreased much further to 62 C and the hydrogen released was 5.9 wt%, which was higher than the theoretical value of 5.6 wt%. The equivalent mole of H released per one equivalent mole of NaAIH was increased to 1.65, compared to 1.5 of NaAIH doped with HfCI alone.
Other Abstract (Other language abstract of ETD)
งานวิจัยนี้ศึกษากลไกการปลดปล่อยไฮโดรเจนของโซเดียมอะลาเนทที่เติมด้วยตัวเร่งปฏิกิริยาโดยเทคนิคเอกซ์เรย์ดิฟแฟรกชัน พบว่าเกิด NaH และ AIH ซึ่งมีบทบาทสำคัญต่อทั้งกระบวนการปลดปล่อยและเก็บไฮโดรเจน และพบ HfH ซึ่ง o
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Recommended Citation
Phurat, Chuttree, "Hydrogen discharging and recharging of NaAIH0subscript 4] and HfCI[subscript 4]-NaAIH" (2006). Chulalongkorn University Theses and Dissertations (Chula ETD). 56916.
https://digital.car.chula.ac.th/chulaetd/56916