Determination of optimum Pd:Ni ratio for Pd _x Ni _{100‐ x} / CNT s formic acid electrooxidation catalysts synthesized via sodium borohydride reduction method

Abstract

Summary The main purpose of this study is to investigate the optimum Pd:Ni molar ratio for carbon nanotube–supported PdNi (PdxNi100‐x/CNT) alloy catalysts toward formic acid electrooxidation (FAE). NaBH4 reduction method was employed for the synthesis of Pd90Ni10/CNT, Pd70Ni30/CNT, Pd50Ni50/CNT, and Pd40Ni60/CNT. Synthesized catalysts were characterized by employing advanced surface analytical techniques, namely, X‐ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption‐desorption, and inductively coupled plasma–mass spectrometry (ICP‐MS). The characterization results showed that all catalysts were successfully synthesized at desired molar composition. Pd90Ni10/CNT displayed the highest specific and mass activities with 2.32 mA/cm2 and 613.9 mA/mg Pd, respectively. Specific activity of the Pd90Ni10/CNT was found approximately 3.6, 2.3, 11.1, and 3.4 times higher than those of Pd70Ni30/CNT, Pd50Ni50/CNT, Pd40Ni60/CNT, and Pd/CNT, respectively. The synergistic effect between Pd and Ni at optimized metal ratio was utilized to obtain an improvement in specific activity. Furthermore, Pd90Ni10/CNT showed the lowest charge transfer resistance (Rct) and a long‐term stability. To our knowledge, this is the first study reporting the optimization of atomic molar composition for PdxNi100‐x/CNT catalysts toward FAE.

Optimization of electrode preparation conditions by response surface methodology for improved formic acid electrooxidation on Pd/MWCNT/GCE

“…In this direction, although the shoulder peak at 0.55 V potential indicates catalyst poisoning, the high intensity of the peak caused by formic acid dehydrogenation indicates a high toxicity tolerance of Pd/MWCNT. The peak at 0.29 V potential in reverse scan shows overall FAEO on the clean electrode surface [23]. The peak intensity in the forward scan (2.67 mA cm − 2 ) is greater than the current density in the reverse scan (2.27 mA cm − 2 ), con rming the high CO poisoning tolerance of Pd/MWCNT.…”

“…It was observed from Fig. 4a that all Pd loading ratio catalysts exhibited a distinct hydrogen adsorption-desorption region in the potential range of -0.2 and 0 V [22,23].…”

Development and application of bimetallic catalysts supported carbon nanotube for 1-propanol electrooxidation

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Recent Advances in Anode Electrocatalysts for Direct Formic Acid Fuel Cells – Part I – Fundamentals and Pd Based Catalysts

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