Electro-oxidation of tri(ammonium) phosphate: New hydrogen source compatible with Ni-based electro-catalysts. (15th July 2022)

• Record Type: Journal Article
• Authors: Barakat, Nasser A.M.; Ahmed, Enas; Farghali, A.A.; Nassar, Mamdouh M.; Tolba, Gehan M.K.; Zaki, Ayman H.
• Is Part Of: International journal of hydrogen energy. Volume 47:Number 60(2022)
• Page Start: 25280
• Page End: 25288
• Publication Date: 2022-07-15
• Subjects: Electro-oxidation -- Nickel-decorated graphene -- Tri(ammonium) phosphate -- Hydrogen; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2022.05.252
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Predominantly, the reported Ni-based electro-catalysts are not applicable anode materials for the alcohols-based proton exchange membrane fuel cells due to the high onset potentials. Alternatively, these non-precious materials can be exploited for hydrogen generation from alcohols with small biases. However, as the nickel oxy(hydroxide) active species is a reactant in the alcohols electro-oxidation reactions, so these materials are exhausted and have to be regenerated. Recently, hydrogen could be extracted from tri(ammonium) phosphate using Ni/C nanostructures as effective catalysts in a simple batch reactor. In this study, electro-oxidation of tri(ammonium) phosphate using Ni-decorated graphene is investigated. The utilized catalyst has been prepared by simple one-pot synthesis procedure; calcination of well mixed nickel acetate/commercial sugar composite. The results indicated that the prepared Ni-decorated graphene is an effective electro-catalyst for tri(ammonium) phosphate oxidation when the nickel content is optimized; 3 wt% metal is the best composition. Moreover, chronoamperometry analysis results indicated that the active layer is not being consumed during the electro-oxidation reaction of the tri(ammonium phosphate) which creates a distinct advantage for this fertilizer over alcohols. Stability of the active layer is attributed to performing Ni(OH)2 /Ni(OOH) redox reaction during tri(ammonium) phosphate electro-oxidation process. Overall, the study opens a new avenue for utilizing hydrogen-rich, cheap and available substances for hydrogen generation using continuously-active non-precious electrodes. Highlights: Electro-oxidation of tri(ammonium) phosphate is introduced. The electro-oxidation does not affect Ni(OOH) content on the surface of the active electrode. The electro-oxidation mechanism is proposed. Compared to alcohols, tri(ammonium) phosphate shows a distinct advantage.