Palladized dysprosium fluoride nanorods as a new performance catalyst in direct methanol fuel cell

Abstract

Summary Fuel cells are a new type of batteries that produce electricity from a continuous source of alcohols as long as fuel is inserted. In this study, decorated palladium nanoparticles (PdNPs) on dysprosium fluoride (DyF3) nanorods (DyFNRs)‐multiwalled carbon nanotubes (MWCNTs) were used for electrooxidation of methanol. DyFNRs were synthesized by the hydrothermal method, and the proposed multifunctional catalyst (DyFNRs/MWCNT‐PdNPs) was identified by several methods such as X‐ray diffraction, elemental mapping images, field emission scanning electron microscopy, energy dispersive analysis of X‐rays, and transmission electron microscopy which demonstrated a uniform distribution and high dispersion of the PdNPs on the supports. The electrocatalytic activity toward methanol electrooxidation on glassy carbon electrode (GCE) with DyFNRs/MWCNT‐PdNPs (DyFNRs/MWCNT‐PdNPs/GCE) was investigated by cyclic voltammetry (CV) and chronoamperometry (CA). Experimental results showed a high improvement in oxidation potential and peak current of methanol electrooxidation by DyFNRs/MWCNT‐PdNPs in comparison to DyFNRs and PdNPs. The values of the catalytic rate constant (k) and physical dimension (Ds) for methanol oxidation on the DyFNRs/MWCNT‐PdNPs/GCE catalyst were calculated 0.008 s−1 and 1.43, respectively. Moreover, the order of reaction was determined to be 0.43 and 0.13 for CH3OH and NaOH, repectively. Finally, the synthesized catalyst was evaluated in direct methanol fuel cell (DMFC). The single DMFC with proposed anodic catalyst, DyFNRs/MWCNT‐PdNPs, indicated a power density of 4.4 mW·cm−2 at a current density of 18 mA·cm−2 in alcohol (1 M) and NaOH (1 M).

A new catalyst for urea oxidation: NiCo2S4 nanowires modified 3D carbon sponge

“…By far, the most studied direct urea cells (DUFC) always employ oxygen as oxidant [4 , 5] . The voltage of DUFC using oxygen as oxidant is 1.15 V, which is a smaller value than those of direct methanol fuel cells (1.21 V) [6] and hydrogen-oxygen fuel cells (1.24 V) [7] . Direct urea hydrogen peroxide fuel cell (DUHPFC) is a new kind of fuel cell using urea as fuel and H 2 O 2 as oxidant.…”

Methanol and proton transport through chitosan‐phosphotungstic acid membranes for direct methanol fuel cell

“…[1][2][3][4] However, two major obstacles that currently prevent the widespread commercial applications of DMFCs are (a) the low activity of reported methanol electrooxidation catalysts to date and (b) crossover of methanol through the polymer electrolyte membrane that leads to a decrease in voltage efficiency. [5][6][7][8][9] In order to overcome these problems, much attention has been paid to study the methanol electrooxidation mechanism on different catalysts, 10,11 and to develop polymer electrolyte membrane matching a high conductivity with a low methanol permeability. [12][13][14][15][16][17] Nafion membranes are commonly used as polymer electrolytes due to their high proton conductivity and to their chemical, mechanical, and thermal stability, 18 although they suffer of relatively high methanol crossover, high manufacturing costs, and they are not environmentally friendly.…”

“…However, two major obstacles that currently prevent the widespread commercial applications of DMFCs are (a) the low activity of reported methanol electrooxidation catalysts to date and (b) crossover of methanol through the polymer electrolyte membrane that leads to a decrease in voltage efficiency 5‐9 . In order to overcome these problems, much attention has been paid to study the methanol electrooxidation mechanism on different catalysts, 10,11 and to develop polymer electrolyte membrane matching a high conductivity with a low methanol permeability 12‐17 …”