A Pt-coated Ni layer supported on a Ni foam catalyst (denoted PtNi/Nifoam) was investigated for the electro-oxidation of the formic acid (FAO) in acidic media. The prepared PtNi/Nifoam catalyst was studied as a function of the formic acid (FA) concentration at bare Pt and PtNi/Nifoam catalysts. The catalytic activity of the PtNi/Nifoam catalysts, studied on the basis of the ratio of the direct and indirect current peaks (jd)/(jnd) for the FAO reaction, showed values approximately 10 times higher compared to those on bare Pt, particularly at low FA concentrations, reflecting the superiority of the former catalysts for the electro-oxidation of FA to CO2. Ni foams provide a large surface area for the FAO, while synergistic effects between Pt nanoparticles and Ni-oxy species layer on Ni foams contribute significantly to the enhanced electro-oxidation of FA via the direct pathway, making it almost equal to the indirect pathway, particularly at low FA concentrations.
Keywords: electro-oxidation; electroless deposition; formic acid; nickel foam; platinum.