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.