International Journal of Energy Research, Vol.43, No.9, 4701-4714, 2019
Palladized dysprosium fluoride nanorods as a new performance catalyst in direct methanol fuel cell
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 (D-s) 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 center dot cm(-2) at a current density of 18 mA center dot cm(-2) in alcohol (1 M) and NaOH (1 M).