Pd nanoparticles anchored to nano-peony CoMn2O4 as an efficient catalyst for H2O2 electroreduction.

Bimetallic oxide CoMn 2 O 4 with nano-peony structure is prepared on Ni foam by a traditional hydrothermal process. Then constant-potential electrodeposition is applied to anchor Pd nanoparticles on CoMn 2 O 4 to form an electrode of Pd nanoparticles modified CoMn 2 O 4 (PCMN electrode) for H 2 O 2 electroreduction. The combination of Pd and CoMn 2 O 4 effectively reduces the dosage of noble metal. Besides, no binder is involved in the preparation which cuts the electrode cost and avoids the poor stability of traditional electrodes produced with binders. Scanning electron microscopy, X-ray diffraction and transmission electron microscopy are operated to investigate the structure and composition of the electrode. And the electrochemical behavior of the electrode is characterized by cyclic voltammetry and chronoamperometry. In 0.7 mol L−1 H 2 O 2 and 3 mol L−1 NaOH, a reduction current density of 580 mA cm−2 (normalized by geometric area) at −0.8 V on the electrode is obtained which reveals large capacity for actual application in H 2 O 2 -based fuel cell. A binder-free electrode of Pd nanoparticles anchored to nano-peony CoMn 2 O 4 was prepared and the synergy effect of Co, Mn and Pd highly improved the catalytic activity toward H 2 O 2 reduction. Unlabelled Image • Pd modified CoMn 2 O 4 electrode with special nano-peony structure was synthesized. • The special nano-peony structure provides more active sites for H 2 O 2 reduction. • The synergy effect of Co, Mn and Pd highly improved the catalytic activity. [ABSTRACT FROM AUTHOR]