Performance characterization of direct formic acid fuel cell using porous carbon-supported palladium anode catalysts

Abstract

Palladium particles supported on porous carbon of 20 and 50 nm pore diameters were prepared and applied to the direct formic acid fuel cell (DFAFC). Four different anode catalysts with Pd loading of 30 and 50 wt% were synthesized by using impregnation method and the cell performance was investigated with changing experimental variables such as anode catalyst loading, formic acid concentration, operating temperature and oxidation gas. The BET surface areas of 20 nm, 30 wt% and 20 nm, 50 wt% Pd/porous carbon anode catalysts were 135 and 90 m 2 /g, respectively. The electro-oxidation of formic acid was examined in terms of cell power density. Based on the same amount of palladium loading with 1.2 or 2 mg/cm 2 , the porous carbon-supported palladium catalysts showed higher cell performance than unsupported palladium catalysts. The 20 nm, 50 wt% Pd/porous carbon anode catalyst generated the highest maximum power density of 75.8 mW/cm 2 at 25 o C. Also, the Pd/porous carbon anode catalyst showed less deactivation at the high formic acid concentrations. When the formic acid concentration was increased from 3 to 9 M, the maximum power density was decreased from 75.8 to 40.7 mW/cm 2 at 25 o C. Due to the high activity of Pd/porous carbon catalyst, the cell operating temperature has less effect on DFAFC performance.

Electrocatalysis by Nanoparticle: Enhanced Electro-Oxidation of Formic Acid at NiOx–Pd Binary Nanocatalysts

“…CO) than Pt-based catalysts. 18 However, Pd catalysts suffer from a gradual deactivation with time, possibly due to the adsorption of some CO-like poisoning species at the Pd surface and/or the dissolution of Pd under highly oxidizing conditions. 19,20 Improvement of the catalytic activity and stability of Pd catalysts toward FAO is recently sought by doping Pd with other metal and/or metal oxide promoters that have the ability to minimize the adsorption of these poisoning species and/or the rate of Pd dissolution.…”

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

“…A comparative study was made for measuring the power density output, ocv, current density using Pd porous carbon supported Pd and unsupported Pd anode catalyst by varying the temperature, oxidants, formic acid fuel concentration parameters. For a 20 nm pore size, maintained at room temperature, with 3 molar concentration of formic acid, 4 mg/cm 2 Carbon supported Pd Anode catalyst loading rate, and supplying oxygen to the cathode, a highest power density of 103.7 mW/cm 2 was achieved and the cell performance increased to 75.8 mW/cm 2 [324] . Jian Huang Zeng et al.…”

“…For a 20 nm pore size, maintained at room temperature, with 3 molar concentration of formic acid, 4 mg/cm 2 Carbon supported Pd Anode catalyst loading rate, and supplying oxygen to the cathode, a highest power density of 103.7 mW/cm 2 was achieved and the cell performance increased to 75.8 mW/cm 2 . [324] Jian Huang Zeng et al investigated and reported the effects on performance and stability of air breathing DFAFC's while using Pt/C, Pd/C & PtPd/C as anode catalyst. On employing Pd/C as anode catalyst, the result indicated excellent catalytic activity and a high power density of 25.1 mW/cm 2 , OCV of 0.77 V, current density as 35 mA/cm 2 (at 0.5v), on being fed 5 molar concentration of formic acid as the fuel.…”

Electrochemically Fabricated Pd–In Catalysts for Carbon Dioxide‐Formate/Formic Acid Inter‐Conversion

“…An attractive use for formic acid is in direct formic acid fuel cells (DFAFCs), enabling the realization of unitized regenerative fuel cell (URFC) systems based on carbon dioxide–formic acid/formate with an inter‐conversion electrode, thus facilitating both the electrochemical reduction of carbon dioxide to formate and the oxidation of formic acid. The concept of URFCs based on carbon dioxide and formic acid/formate was established very recently .…”