Pd Nanoparticle Size Effect of Anodic Catalysts on Direct Formic Acid Fuel Cell Initial Performance: Development of a Mathematical Model and Comparison with Experimental Results

Abstract

Direct Formic Acid Fuel Cell (DFAFC) is considered as a promising liquid fuel cell. Here, the effect of palladium particle size (dPd) of anodic DFAFC catalysts on initial power density was studied. The number of electrochemically available Pd atoms on the surface of Pd nanocrystallites in the anodes were determined experimentally. The cathode potential as a function of the current density has been measured. The mathematical model describing the effect of dPd on DFAFC performance has been developed. It was assumed that: (i) Pd crystallites have shape of cuboctahedron, (ii) Pd atoms lying on edges and corners are inactive, (iii) The activity of Pd atoms lying on crystallite (111) and (100) facets do not change with dPd. The mathematical model describes well the effect of current density and dPd on fuel cell voltage and power density. The model predicts that maximum power density is reached at dPd=2.4 nm.

A Biphasic Strategy to Synergistically Accelerate Activation and CO Spillover in Formic Acid Oxidation Catalysis

“…(e) Steady-state polarization and power density curves of MEA using 5 M HCOOH in the anode at 80 °C. (f) MEA power density comparison of h / c -PtPb/C with the state-of-the-art DFAFC catalysts. ,,,,,− …”

Recent Advances in Anode Electrocatalysts for Direct Formic Acid Fuel Cells – Part I – Fundamentals and Pd Based Catalysts

“…Theoretical model was found to match well with the experimental results. According to the model, 2.4 nm crystallite size of Pd corresponds to the maximum power density [67] . Lue et al.…”

Effect of Synchrotron X-ray Irradiation Time on the Particle Size and DFAFC Performance of Pd/CNT Catalysts

“…Pd nanocrystals with an average particle size of 4.1 nm exhibited the highest activity of 70 mA/cm 2 for formic acid oxidation reaction [ 26 ]. In addition, Chiou et al developed a mathematical model to determine the optimal Pd particle size for DFAFC performance and predicted that the cuboctahedron-shaped Pd with a particle size of 2.4 nm is preferred [ 27 ].…”