The surface coating of a gas reaction electrode with layered double hydroxides (LDHs) featuring various electrode catalyst activities was prepared via electrodeposition and the subsequent crystal growth of LDHs. LDH formation was confirmed by X-ray diffraction and Raman scattering measurements after subsequent crystal growth on respective electrodeposited precursor films in Ni-Fe and Zn-Al LDH systems. However, the crystal growth of LDHs in Ni-Mn and Cu-Mn systems was observed on the Mg-Al LDH-electrodeposited films. LDH films were also deposited on the surface of a carbon paper electrode with a rugged surface via electrodeposition and subsequent crystal growth. Using the prepared LDH-coated carbon paper electrodes, the electrode catalytic activity for the oxygen reduction reaction (ORR) was examined. For Ni-Mn, Ni-Al and Ni-Fe LDH-coated carbon paper electrodes, the threshold voltages of the ORR decreased. Hence, the LDHs electrodeposited on a gas reaction electrode have high electrochemical catalytic activity for the ORR.
