Platinum-Silver Alloy Nanoballoon Nanoassemblies with Super Catalytic Activity for the Formate Electrooxidation

Abstract

Alkaline direct formate fuel cells (ADFFC) are emerging as a propitious candidate for green energy conversion devices. However, the poor electrocatalytic activity and stability of anodic electrocatalysts are immense challenges for its full-scale commercialization. In the current work, Pt−Ag alloy nanoballoon nanoassemblies (ANBNSs) were easily synthesized by the galvanic replacement reaction between threedimensionally multibranched Ag nanoflowers and K 2 PtCl 4 . Electrochemical results exhibit that Pt−Ag ANBNSs have a nearly 19.3-fold activity enhancement for the formate oxidation reaction (FOR) over commercial Pt nanoparticles in alkaline media, as well as a higher resistance to CO poisoning and excellent durability for the FOR. This work demonstrates that Pt−Ag ANBNSs are indeed highly promising active and durable electrocatalysts for the FOR due to the integration of geometric/electronic effects and porous architecture.

A low temperature aqueous formate fuel cell using cobalt hexacyanoferrate as a non-noble metal oxidation catalyst

“…A large, irreversible anodic current is observed at potentials >+0.35 V vs. NHE in the presence of formate that is not observed in the pH 13 electrolyte alone. In other studies with Pd [32][33][34] or Pt [35][36][37] catalysts several oxidation peaks are instead observed in both forward and reverse scans. These peaks are ascribed to the direct formate oxidation followed by formation of Pd or Pt oxide layers and/or adsorption of poisoning intermediate species (in the forward scan) and to the further oxidation of these reaction intermediates, known as indirect formate oxidation (in the reverse scan).…”

Benchmarking Catalysts for Formic Acid/Formate Electrooxidation

“…Other basic Pt electrodes configurations are Pt net [57], Pt bead [58] and Pt single-crystalline electrodes, especially those containing the (111) exposed to the solution given the greater tolerance to CO poisoning of this specific lattice plane [59,60,81]. While Pt disk electrodes have the advantage of simplicity and ease of use, several authors employ Pt nanoparticles deposited on an electrode (typically glassy carbon disk) as reference materials to compare their further developed electrocatalysts [62,64,65,72]. These Pt nanoparticles usually show higher electrocatalytic activity than Pt disks under comparable conditions.…”

“…The greatest dissolution features were observed when the experiments were performed in a CO-saturated electrolyte implying that the indirect oxidation pathway (i.e., through CO adsorption and oxidation) plays a key role in formate electrooxidation using PtRu as the catalyst. Other Pt-based alloys have been tested in formic acid/formate electrooxidation such as PtFe [79], PtAu [67,90], PtAg [65], PtCo [66], PtCu [68], PdPt [39,71,73,91,92], PtBi [69,93] or PtSn [68,93,94] (Table 2). Indeed, the use of Bi, Sb, As, Pb, Sn and Ge as dopants for Pt has been investigated from several decades ago, finding optimum loadings of around 50% in most cases [93,94].…”

Solvent‐Mediated Shell Dimension Reconstruction of Core@Shell PdAu@Pd Nanocrystals for Robust C1 and C2 Alcohol Electrocatalysis

“…For one thing, the traditional adopted strategies often involve the using of organic ligands, surfactants, and capping agents such as hexadecyl trimethyl ammonium bromide, oleylamine, which makes it hard to clean the organic residues on the surface of products. [ 27–29 ] The superficial residual would impede the surface reaction that has an unfavorable effect on the electrocatalytic properties. [ 30,31 ] For another, conventional synthetic methods for obtain core@shell structures usually involve two or more steps by “nucleation‐ epitaxial growth”, which cost a substantial amount of time and effort, and thus lack of convenience and the quickness.…”