Efficient Direct Formic Acid Fuel Cells (DFAFCs) Anode Derived from Seafood waste: Migration Mechanism

Abstract

Commercial Pt/C anodes of direct formic acid fuel cells (DFAFCs) get rapidly poisoned by in-situ generated CO intermediates from formic acid non-faradaic dissociation. We succeeded in increasing the Pt nanoparticles (PtNPs) stability and activity for formic acid oxidation (DFAFCs anodic reaction) by embedding them inside a chitosan matrix obtained from seafood wastes. Atop the commercial Pt/C, formic acid (FA) is predominantly oxidized via the undesired poisoning dehydration pathway (14 times higher than the desired dehydrogenation route), wherein FA is non-faradaically dissociated to CO resulting in deactivation of the majority of the Pt active-surface sites. Surprisingly, PtNPs chemical insertion inside a chitosan matrix enhanced their efficiency for FA oxidation significantly, as demonstrated by their 27 times higher stability along with ~400 mV negative shift of the FA oxidation onset potential together with 270 times higher CO poisoning-tolerance compared to that of the commercial Pt/C. These substantial performance enhancements are believed to originate from the interaction of chitosan functionalities (e.g., NH2 and OH) with both PtNPs and FA molecules improving FA adsorption and preventing the PtNPs aggregation, besides providing the required oxygen helping with the oxidative removal of the adsorbed poisoning CO-like species at low potentials. Additionally, chitosan induced the retrieval of the Pt surface-active sites by capturing the in-situ formed poisoning CO intermediates via a so-called “migration mechanism”.

Free Standing Nanoporous Palladium Alloys as CO Poisoning Tolerant Electrocatalysts for the Electrochemical Reduction of CO2 to Formate

“…This presents a distinct advantage over process development for the reduction of CO 2 to more reduced products including alcohols and hydrocarbons. HCOO – /HCOOH has great utility as both an electrochemical fuel − and a chemical precursor, − making it a more desirable reduced product than CO. The high overpotentials, as large as 1 V in some cases, ,,,,− on traditional HCOO – /HCOOH evolving metals, however, is a significantly limiting barrier.…”

Hierarchically structured iron-doped silver (Ag–Fe) lotus flowers for an efficient oxygen reduction reaction

“…Development of efficient catalysts for the sluggish oxygen reduction reaction (ORR) plays a pivotal role in the overall performance and cost of polymer electrolyte membrane fuel cells (PEMFCs), which are considered as an auspicious alternative to traditional technologies based on fossil resources. However, their commercialization is obstructed by high cost and poor performance of their commercial Pt-based electrodes [1][2][3][4][5][6][7][8][9][10][11] . The major performance losses in PEMFC originate from Pt particles agglomeration and low tolerance of Pt towards various organic and inorganic contaminants produced in-situ from degradation of various PEMFC components, as well as the platinum´s poor tolerance against different anode impurities which cross-over from the anode through the membrane and result in a significant reduction of the PEMFC efficiency 9,10,[12][13][14] .…”

Bifunctional Tailoring of Platinum Surfaces with Earth Abundant Iron Oxide Nanowires for Boosted Formic Acid Electro-Oxidation

“…All catalysts were characterized electrochemically before and after modification with FeOx by measuring their characteristic CVs in 0.5 M H 2 SO 4 (Figure 1), where the corresponding real surface areas of the FeOx/Pt catalysts could be estimated assuming a reference value of 210 µC•cm −2 for H ads/des [33].…”