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Shape-tuned, surface-active and support-free silver oxygen reduction electrocatalyst enabled high performance fully non-PGM alkaline fuel cell
- Source :
- RSC advances. 11(40)
- Publication Year :
- 2021
-
Abstract
- Exploring non-platinum group metal (n-PGM) based efficient oxygen reduction reaction (ORR) electro-catalysts is highly important for realizing advancement in sustainable next generation-alkaline anion exchange membrane fuel cells (AAEMFCs). Herein, we demonstrate a new “hierarchical shape tuning approach” for the synthesis of controlled sized and shaped non-PGM based Ag ORR electro-catalysts with surface active nano-islands. Hierarchical shapes ranging from spherical (S-AgNs), worm-in-sphere, sphere-in-worm and vermiform (worm-like) Ag nanostructures (V-AgNs) were obtained by precisely varying the ratios of capping agent to dual reducing agents in water at ambient conditions. Compared to S-AgNs, V-AgNs revealed a higher mass normalized ORR Tafel activity (0.303 A mgAg−1 at 0.9 V), onset (1.06 V) and half wave (0.78 V) potentials and higher retention of limiting current density (>88%) after 5000 cycles in 0.5 M potassium hydroxide (KOH) solution attributable to their unique worm like morphology with surface active nano-islands and support free-nature enabled better catalyst utilization. In a fully “non-PGM AAEMFC” (n-PAAEMFC), V-AgNs exhibited the highest fuel cell activity of 115.6 mW cm−2 and stable short-term durability (∼240 h) compared to S-AgNs (41.3 mW cm−2) and previously reported fully n-PAAEMFCs indicating their potential use in next-generation alkaline fuel cells.
- Subjects :
- Tafel equation
Alkaline fuel cell
Potassium hydroxide
Materials science
Ion exchange
Reducing agent
General Chemical Engineering
Limiting current
02 engineering and technology
General Chemistry
010402 general chemistry
021001 nanoscience & nanotechnology
Electrocatalyst
01 natural sciences
0104 chemical sciences
Catalysis
chemistry.chemical_compound
Chemical engineering
chemistry
0210 nano-technology
Subjects
Details
- ISSN :
- 20462069
- Volume :
- 11
- Issue :
- 40
- Database :
- OpenAIRE
- Journal :
- RSC advances
- Accession number :
- edsair.doi.dedup.....c27588f6c10220dd7e464aa12cce8807