Surface engineering of nanotubular ferric oxyhydroxide "goethite" on platinum anodes for durable formic acid fuel cells. (1st January 2022)

• Record Type: Journal Article
• Authors: Al-Qodami, Bilquis Ali; Alalawy, Hafsa H.; Al-Akraa, Islam M.; Sayed, Sayed Youssef; Allam, Nageh K.; Mohammad, Ahmad M.
• Is Part Of: International journal of hydrogen energy. Volume 47:Number 1(2022)
• Page Start: 264
• Page End: 275
• Publication Date: 2022-01-01
• Subjects: Platinum nanoparticles -- Iron oxide -- Electrocatalysis -- Liquid fuel cells -- Poisoning; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2021.10.037
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: A peerless inexpensive electrochemical engineering of spherical Pt nanoparticles (nano-Pt: ca. 100 nm in average diameter) was achieved with intersected ferric oxyhydroxide nanotubes (α-FeOOH (goethite): ca. 20 nm in average diameter). The FeOOH@Pt catalyst exhibited ca. 2.5 and 1.94-times increases in the catalytic activity and poisoning tolerance, respectively, of the formic acid electro−oxidation (FAO) – the anodic reaction in the direct formic acid fuel cells (DFAFCs). Surprisingly, with a post-activation of the FeOOH@Pt catalyst at 0.48 V vs. reversible hydrogen electrode (RHE) in 0.2 mol L −1 NaOH, a favorable Fe 2+ /Fe 3+ transformation succeeded to eliminate the permanent CO poisoning of Pt that impaired the catalytic performance of DFAFCs. This was synchronized (relatively to nano-Pt) with a four-fold increase in the catalytic efficiency, ca. −174 mV shift in the onset potential, and eightfold enhancement in the catalyst's durability for FAO. The activated FeOOH@Pt catalyst also showed a mass activity of 296 mA mg −1 Pt (at 0.8 V), which was ca. nine times higher than that (34 mA mg −1 Pt ) of the commercial Pt/C catalyst. The ascertained improvement in the electron transfer at the FeOOH@Pt surface foresees quick industrialization for DFAFCs. Graphical abstract: TOC. A simple layer-by-layer electrochemical assembly and a post-activation of a peerless inexpensive FeOOH/Pt/GC nanostructured catalyst was recommended for "mitigated CO-poisoning" formic acid electro−oxidation. Image 1 Highlights: An efficient and robust FeOOH/Pt anodic catalyst was developed for the direct formic acid fuel cells (DFAFCs). The catalyst's activation at 0.48 V vs. RHE in NaOH resulted in a boosted (fourfold) catalytic performance. The activation enriched the catalyst surface with α-FeOOH (goethite phase). The electronic properties of Pt were tuned to accelerate the charge transfer of FAO. The peerless inexpensive modification of Pt with FeOOH will sustain the market to realize DFAFCs.