Carbon nanotube supported direct borohydride fuel cell anode catalysts: the effect of catalyst loading

Authors : Hilal DEMİR KIVRAK, Aykut CAGLAR, Tulin AVCI HANSU, Ömer ŞAHİN

Pages : 1-10

View : 15 | Download : 12

Publication Date : 2020-06-30

Article Type : Research Paper

Abstract :At present, monometallic CNT supported Pd electrocatalysts insert ignore into journalissuearticles values(Pd/CNT); are prepared at varying Pd loadings via sodium borohydride insert ignore into journalissuearticles values(NaBH4); reduction method to investigate their NaBH4 electrooxidation activities. These monometallic Pd/CNT catalysts are characterized by X-ray Diffraction insert ignore into journalissuearticles values(XRD);, N2 adsorption-desorption, Fourier-Transform Infrared Spectroscopy insert ignore into journalissuearticles values(FTIR);, and Scanning Electron Microscopy-Energy Dispersive X-ray analysis insert ignore into journalissuearticles values(SEM-EDX);. Characterization results are revealed that Pd/CNT metallic Pd with a face center cubic structure is detected. The crystallite size corresponding to insert ignore into journalissuearticles values(1 1 1 ); plane is found as 5.87 nm for 30% Pd/CNT catalyst. The average pore size, pore-volume, and Brunauer, Emmet ve Teller insert ignore into journalissuearticles values(BET); surface area of Pd/CNT are obtained as 24.5 nm, 0.93 cm³/g, and 129.48 cm2/g, respectively. From the SEM-EDX results, it indicates that the Pd metal is homogeneously distributed in the carbon structures. NaBH4 electrooxidation measurements are performed with cyclic voltammetry insert ignore into journalissuearticles values(CV);, chronoamperometry insert ignore into journalissuearticles values(CA);, and electrochemical impedance spectroscopy insert ignore into journalissuearticles values(EIS);. The effect of Pd loading insert ignore into journalissuearticles values(0.1-70.0 %); for NaBH4 electrooxidation is investigated via CV. The 30% Pd/CNT catalyst exhibits the highest electrochemical activity with a current density of 16.5 mA cm-2. By altering Pd loading, catalyst surface electronic structure changes significantly, leading to enhanced NaBH4 electrooxidation activity. CA and EIS measurement results are agreement with CV results. As a conclusion, it is clear that Pd/CNT catalysts are promising catalysts for direct borohydride fuel cells.
Keywords : Pd CNT, fuel cell, sodium borohydride, catalyst