Bimetallic Nanocomposites of Palladium (100) and Ruthenium for Electrooxidation of Ammonia
Symmmetrically oriented Pd (100) and its bimetallic Pd (100)Ru electrocatalysts were chemically synthesized and their conductive properties employed in the electrochemical oxidation of ammonia. Electrochemical data based on EIS, SWV and CV revealed that the Pt/Pd (100)Ru electrode showed a better conductivity and higher catalytic response towards the electrooxidation of ammonia compared to Pt/Pd (100) electrode. This was demonstrated by the EIS results where Pt/Pd (100)Ru gave a charge transfer resistance (Rct) of 48.64 Ω, high exchange current and lower time constant (5.2738 x 10-1A and 3.2802 x 10-7 s /rad) values while the Pt/Pd (100) had values of 173.2 Ω, 1.4811 x 10-1A and 4.8321 10-7 s /rad. The drastic drop in Rct highlights the superiority of the Pt/Pd (100)Ru over the Pt/Pd (100) and confirms that facile interfacial electron transfer processes occur on the Pt/Pd (100)Ru electrode during the electrocatalytic ammonia oxidation. Investigations through voltammetry revealed that the Pt/Pd (100)Ru had a higher peak current density and a shift in potential to more negative values at ≈ -0.2 V and ≈ -0.4 V. The EASA value of Pt/Pd (100)Ru was found to be 119.24 cm2 whereas Pt/Pd (100) had value of 75.07 cm2. The high electrochemically active surface area of Pd (100)Ru at 119.24 cm2 compared to the 75.07 cm2 for Pd (100) strengthened this observation in performance between the two catalysts for ammonia electrooxidation.
Emmanuel Iheanyichukwu Iwuoha and Priscilla Gloria Lorraine Baker
N. Matinise et al., "Bimetallic Nanocomposites of Palladium (100) and Ruthenium for Electrooxidation of Ammonia", Journal of Nano Research, Vol. 44, pp. 100-113, 2016