Green ammonia production has been an important topic that is being researched during the last decades due to the increasing demand and to cut down CO2 emissions. One of the promising pathways to achieve green chemical energy synthesis is the Photoelectrochemical (PEC) approach. To realize low-cost and scalable green ammonia production, the direct integration of solar photovoltaic modules and catalysts as a Photovoltaic-Electrochemical (PV-EC) system is highly suitable. In this study, Molybdenum Carbide(Mo2C) decorated with different metal nanoparticles (Pt, Pd, Ru) is being investigated as a potential nitrate reduction (NO3RR) to ammonia. Here various metal-decorated M o2C was successfully synthesized by the chemical reduction method. The metal-decorated M o2C is characterized by Transmission Electron Microscopy(TEM), Raman Spectroscopy, and X-ray diffraction(XRD) analysis and confirmed the formation. Initially, electrocatalytic NO3RR was carried out, and Pt decorated Mo2C was found to demonstrate high Faradic efficiency and NH3 of 30% and 4400 μg/h/cm2. Next, PV-EC was carried out, and a stable solar-powered NO3RR was carried out with Pt-M o2C and Si PV module. The proposed system delivers a yield of 600 ug/h/cm2 and a Faradic Efficiency of 7% .

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 μmol cm-2 h-1) at -3.1V (cell voltage), through catalytic nitrate (𝑁𝑂3−) 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 värld av ohållbar tillväxt och alltmer katastrofala klimathändelser är strävan efter hållbarhet öppen. Elektrokemisk ammoniaksyntes (EAS) är en miljövänlig metod för grön ammoniakproduktion. Denna teknik kräver främst el, som kan förses från förnybara källor, för energitillförsel och kan användas på ett decentraliserat sätt, vilket minskar transportutsläppen och komplexiteten. Grön ammoniak kan hjälpa mänskligheten som vätgasbärare, energilagring och hållbart gödningsmedel. Hållbara alternativ är dock fortfarande långt ifrån att uppnå produktionsnivån för nuvarande teknik, nämligen Haber-Bosch-processen. Detta experimentella arbete undersöker möjligheten att implementera en ny strategi för elektrokemisk ammoniaksyntes genom membranfri porösväggar. Denna forskning handlar huvudsakligen om två experimentella faser: den första handlar om enkelfack (SC) cellelektrokemisk uppsättning, och den andra en membranfri porösväggar (PW) celluppsättning. Den förstnämnda användes för att få kunskap om membranfritt cellbeteende, som sedan applicerades på det senare, vars mål var att uppnå ammoniaksyntes. Det har visats att den just nämnda tekniken kan uppnå högströmtätheter (707.4 mA cm-2) och hög ammoniakproduktionshastighet (1727.9 μmol cm-2 h-1) vid -3.1V (cellspänning), genom katalytiskt nitrat (𝑁𝑂3−) reduktion, på nickelfosfidarkatod i en vattenhaltig natriumhydroxidelektrolytlösning. Å andra sidan visar resultaten en låg faradaisk effektivitet, bara 43%. Även om resultaten delvis validerades genom litteratur- och kontamineringstester, måste isotopmärkningsexperiment genomföras för mer pålitliga uppskattningar. Dessa fynd lägger till ytterligare ett lovande perspektiv på området elektrokemisk ammoniaksyntes.