Mehanokemijska sinteza i karakterizacija novih amidoborana za pohranu vodika

master's thesis

• Title (english): Mechanochemical synthesis and characterization of new amidoboranes for hydrogen storage
• Author: Vedrana Krajnović
• Mentor: Fabio Faraguna (mentor)
• Mentor: Nikola Biliškov (komentor)
• Committee member: Fabio Faraguna (predsjednik povjerenstva)
• Committee member: Ante Jukić (član povjerenstva)
• Committee member: Nikola Biliškov (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2020-09-21, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Basic Technical Sciences

Abstract

Vodik ima potencijala da igra ključnu ulogu u budućem održivom energetskom sustavu kao nosilac obnovljive energije koja treba zamijeniti ugljikovodike. Problem tog koncepta je nedovoljno usavršen sustav skladištenja vodika s obzirom na zahtjeve za spremnike vodika. Za ovu svrhu sve se češće istražuju kompleksni hidridi s visokim gravimetrijskim i volumetrijskim kapacitetom. U ovom radu istraživana je sinteza Li[Al(NH2BH3)4] i Na[Al(NH2BH3)4] primjenom mehanokemijske sinteze i sinteze starenjem. Dobiveni spojevi karakterizirani su IR spektroskopijom metodom prigušene totalne refleksije (ATR), difrakcijom rendgenskog zračenja na prahu (PXRD-om), TPD-MS-om i DSC-TG-om. Na temelju dobivenih rezultata uočeno je da je mehanokemijska sinteza jednostavnija, brža i učinkovitija metoda sinteze ovih spojeva u odnosu na sintezu starenjem. Također je uočeno da se kombinacijom NH3BH3 s LiAlH4, Li3AlH6, odnosno NaAlH4 smanjuje temperatura dehidrogeniranja, te se u slučaju mehanokemijski dobivenog Li[Al(NH2BH3)4] smanjuje količina nusprodukata kao što su borazin, diboran i amonijak u odnosu na NH3BH3. Problem kod ovih materijala je to što se ne mogu rehidrogenirati u praktično dostupnim uvjetima. Otkrivene su potencijalne metode djelomične rehidrogenacije ovih spojeva, ali potrebna su daljnja istraživanja da bi se te metode potvrdile.

Abstract (english)

Hydrogen has the potential to play a key role in the future sustainable energy system as a carrier of renewable energy that will replace hydrocarbons. The problem with using hydrogen is its storage capability with respect to the requirements for hydrogen tanks. For this purpose, complex hydrides with high gravimetric and volumetric capacity are increasingly being investigated. In this paper, the synthesis of Li[Al(NH2BH3)4] and Na[Al(NH2BH3)4] was studied using mechanochemical synthesis and aging synthesis. The obtained compounds were characterized by IR spectroscopy in attenuated total reflection (ATR) mode, powder X-ray diffraction (PXRD), TPD-MS and DSC-TG. Based on the obtained results, it was noticed that mechanochemical synthesis is a simpler, faster and more efficient method of synthesis of these compounds compared to synthesis by aging. It was also observed that the combination of NH3BH3 with LiAlH4, Li3AlH6 or NaAlH4, repectively, reduces the dehydrogenation temperature, and in the case of mechanochemically produced Li[Al(NH2BH3)4] the amount of by-products such as borazine, diborane and ammonia decreases compared to NH3BH3. The problem with these materials is that they cannot be rehydrogenated in practical conditions. Potential methods of partial rehydrogenation of these compounds have been identified, but further research is needed to verify these methods.

• Keywords: vodik; borazan; litijev aluminijev amidoboran; Li[Al(AB)4]; natrijev aluminijev amidoboran; Na[Al(AB)4]; mehanokemijska sinteza; sinteza starenjem
• Keywords (english): hydrogen; ammonia borane; lithium aluminium amidoborane; Li[Al(AB)4]; sodium aluminium amidoborane; Na[Al(AB)4]; mechanochemical synthesis; aging synthesis
• Language: croatian
• URN:NBN: urn:nbn:hr:149:700678
• Study programme: Title: Applied Chemistry - Graduate study; specializations in: Environmental chemistry and green technologies, Advanced materials and technologies, Applied organic chemistry; Course: Advanced materials and technologies; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra primijenjene kemije (magistar/magistra primijenjene kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-03-05 10:40:22