Abstract:The formation of nanoporous Pd was studied by electro-chemical dealloying a rapidly-quenched Al₇₀Pd₁₇Fe₁₃ quasicrystal alloy in dilute NaCl aqueous solution, and the electro-catalytic activity of the nanoporous Pd towards methanol electro-oxidation was evaluated by cyclic voltammetry in 1 mol/L KOH solution. XRD and TEM analyses revealed that nano-decomposition of quasicrystal grains occurred in the initial stage of dealloying, and the fully dealloyed sample was composed of FCC-Pd phase. Scanning electron microscopy observation indicated that a maze-like nanoporous pattern was formed in the dealloyed sample, consisting of percolated pores of 5-20 nm in diameter in a skeleton of randomly-orientated Pd nano-ligaments with a uniform thickness of ~5 nm. A retention of ~12 at.% Al in the Pd nano-ligments was determined by energy dispersive X-ray spectroscopy (EDS). The nanoporous Pd demonstrated obvious electro-catalytic activity towards methanol electro-oxidation in alkaline environment.

Key words: nanoporous palladium; Al-Pd-Fe quasicrystal; dealloying; electro-catalytic activity