n a world of unsustainable growth and increasingly catastrophic climate events, the quest for sustainability is open. Electrochemical ammonia synthesis (EAS) represents an eco-friendly means for green ammonia production. This technology mainly requires electricity, which can be harvested from renewable sources, as its energy input, and can be employed in a decentralized fashion, cutting down transport emissions and complexity. Green ammonia could help humanity as a hydrogen carrier, energy storage and sustainable fertilizer. However, sustainable alternatives are still far from achieving the production rates of the current adopted technology, namely the Haber-Bosch process. The present experimental-based investigation explores the feasibility of implementing a new membrane-less porous walls approach to electrochemical ammonia synthesis. This research mainly revolves around two experimental phases: the first considering a single compartment (SC) cell electrochemical set-up, and the second a membrane-less porous walls (PW) cell set-up. The former was used to gain knowledge regarding membrane-less cell behaviour, which then was applied to the latter, whose aim was to achieve ammonia synthesis. It was demonstrated that this approach can achieve high current densities (707.4 mA cm-2) and high ammonia production rate (1727.9 ÎŒmol cm-2 h-1) at -3.1V (cell voltage), through catalytic nitrate (đđ3â) reduction, on nickel phosphide sheet cathode, in an aqueous sodium hydroxide electrolyte solution. On the contrary, it shows low faradaic efficiency, only 43%. Even if the results were partially validated by literature and contamination tests, isotope labelling experiments need to be conducted for more reliable estimates. These findings add another promising perspective to the field of electrochemical ammonia synthesis. / I en vĂ€rld av ohĂ„llbar tillvĂ€xt och alltmer katastrofala klimathĂ€ndelser Ă€r strĂ€van efter hĂ„llbarhet öppen. Elektrokemisk ammoniaksyntes (EAS) Ă€r en miljövĂ€nlig metod för grön ammoniakproduktion. Denna teknik krĂ€ver frĂ€mst el, som kan förses frĂ„n förnybara kĂ€llor, för energitillförsel och kan anvĂ€ndas pĂ„ ett decentraliserat sĂ€tt, vilket minskar transportutslĂ€ppen och komplexiteten. Grön ammoniak kan hjĂ€lpa mĂ€nskligheten som vĂ€tgasbĂ€rare, energilagring och hĂ„llbart gödningsmedel. HĂ„llbara alternativ Ă€r dock fortfarande lĂ„ngt ifrĂ„n att uppnĂ„ produktionsnivĂ„n för nuvarande teknik, nĂ€mligen Haber-Bosch-processen. Detta experimentella arbete undersöker möjligheten att implementera en ny strategi för elektrokemisk ammoniaksyntes genom membranfri porösvĂ€ggar. Denna forskning handlar huvudsakligen om tvĂ„ experimentella faser: den första handlar om enkelfack (SC) cellelektrokemisk uppsĂ€ttning, och den andra en membranfri porösvĂ€ggar (PW) celluppsĂ€ttning. Den förstnĂ€mnda anvĂ€ndes för att fĂ„ kunskap om membranfritt cellbeteende, som sedan applicerades pĂ„ det senare, vars mĂ„l var att uppnĂ„ ammoniaksyntes. Det har visats att den just nĂ€mnda tekniken kan uppnĂ„ högströmtĂ€theter (707.4 mA cm-2) och hög ammoniakproduktionshastighet (1727.9 ÎŒmol cm-2 h-1) vid -3.1V (cellspĂ€nning), genom katalytiskt nitrat (đđ3â) reduktion, pĂ„ nickelfosfidarkatod i en vattenhaltig natriumhydroxidelektrolytlösning. Ă andra sidan visar resultaten en lĂ„g faradaisk effektivitet, bara 43%. Ăven om resultaten delvis validerades genom litteratur- och kontamineringstester, mĂ„ste isotopmĂ€rkningsexperiment genomföras för mer pĂ„litliga uppskattningar. Dessa fynd lĂ€gger till ytterligare ett lovande perspektiv pĂ„ omrĂ„det elektrokemisk ammoniaksyntes.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:kth-337099 |
| Date | January 2023 |
| Creators | Gelain, Francesco |
| Publisher | KTH, Skolan för industriell teknik och management (ITM) |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | Swedish |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | TRITA-ITM-EX ; 2023:477 |
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