Clean Electrochemical Synthesis of Pd–Pt Bimetallic Dendrites with High Electrocatalytic Performance for the Oxidation of Formic Acid

Abstract

Pd–Pt bimetallic catalysts with a dendritic morphology were in situ synthesized on the surface of a carbon paper via the facile and surfactant-free two step electrochemical method. The effects of the frequency and modification time of the periodic square-wave potential (PSWP) on the morphology of the Pd–Pt bimetallic catalysts were investigated. The obtained Pd–Pt bimetallic catalysts with a dendritic morphology displayed an enhanced catalytic activity of 0.77 A mg–1, almost 2.5 times that of the commercial Pd/C catalyst reported in the literature (0.31 A mg–1) in acidic media. The enhanced catalytic activity of the Pd–Pt bimetallic catalysts with a dendritic morphology towards formic acid oxidation reaction (FAOR) was not only attributed to the large number of atomic defects at the edges of dendrites, but also ascribed to the high utilization of active sites resulting from the “clean” electrochemical preparation method. Besides, during chronoamperometric testing, the current density of the dendritic Pd–Pt bimetallic catalysts for a period of 3000 s was 0.08 A mg−1, even four times that of the commercial Pd/C catalyst reported in the literature (about 0.02 A mg−1).

Recent Advances in Anode Electrocatalysts for Direct Formic Acid Fuel Cell‐II‐Platinum‐Based Catalysts

“…The current density of dendritic Pd −Pt catalysts was measured to be 0.08 A ⋅ mg −1 after 3000 s for chronoamperometric testing. This value is four times that of a commercial Pd/C catalyst [147] …”

“…This value is four times that of a commercial Pd/C catalyst. [147] Modification of Pt (111) with Bi, [148] Sb, [149,150] and Pb [151] improves the performance of the catalysts for FAO. The challenge lies in the use of these results to the NPs.…”

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

“…Palladium occupies the same group in the periodic table as Pt does. It has only 0.77 % lattice constant mismatch [79] . This explains why Pd shows property similar to Pt such as structure, electronic property, atomic size and crystal structure with the added advantage that it cheaper and more available than Pt.…”

“…It has only 0.77 % lattice constant mismatch. [79] This explains why Pd shows property similar to Pt such as structure, electronic property, atomic size and crystal structure with the added advantage that it cheaper and more available than Pt. Moreover, it is well established that FAO over Pd and its alloys takes place via direct mechanism, which avoids the CO poisoning.…”