سید رضا حسینی زوارمحله

Direct formic acid fuel cells have attracted considerable interest as new generation of power sources [1]. Some benefits of formic acid (HCOOH) as a natural biomass compared to methanol are its non-toxic, non-explosive and non-flammable properties at room temperature as well as its less positive standard oxidation potential [2]. It has been recognized that HCOOH oxidation is more facile on Pd modified by a second element, such as Cu than on pure Pd and the catalyst deactivation is much slower [3]. The Cu, which is much cheaper than Pd, has been considered to be an important core to synthesize Pd-based bimetallic catalysts. On the other hand, conducting polymers are suitable supports for catalyst nanoparticles due to their high surface area, good conductivity, and chemical stability providing better access of reactants to the catalyst. In this work, a carbon paste electrode was modified by electro-polymerization of 2MA monomer by potentiodynamic method in aqueous 0.5 M H2SO4 solution containing SDS and 5.0 mM 2MA for construction of the P2MA-SDS/CPE and electro-deposition of Cu nanoparticles from H2SO4 solution containing CuSO4 by using potentiostatic method. Following Cu deposition and immersion into PdCl2/H2SO4 solution, the as-prepared Pd-Cu/P2MA-SDS nanocomposite was scanned repeatedly in the cleaning H2SO4 solution, ensuring that any unreacted Cu was anodically dissolved during exposure to positive potentials. The Pd-Cu nanoparticles are prepared through spontaneous and irreversible reaction via galvanic replacement between PdII ions and Cu particles. The obtained results show that the Pd-Cu exhibited significantly high current density of HCOOH oxidation compared to other catalysts and utilization of Cu nanoparticles enhances the electro-catalytic activity towards oxidation. The enhanced performance is proposed to come from the synergetic effect between Pd-Cu nanoparticles and P2MA-SDS film. Also, P2MA-SDS film with an abundant amount of electrons will generate