Partially reduced Ni2+, Fe3+-layered double hydroxide for ethanol electrocatalysis

Direct alcohol fuel cells can directly convert the chemical energy stored in small liquid alcohol molecules into electricity. The non-noble metal oxides and oxyhydroxides have poor electric conductivity, limiting their electrochemical performance. Herein, Ni3Fe/NiFe(OH)(x) heterostructure with Ni3Fe alloy nanoparticles confined in amorphous NiFe(OH)(x) matrix is facilely fabricated by partial reduction of Ni2+, Fe3+-layered double hydroxide (NiFe-LDH) precursor in flowing hydrogen. Small Ni3Fe particles with about 4 nm diameter are clearly recognized after reduction at 250 degrees C. Further raising the reduction temperature to 350 degrees C results in a greater degree of segregation of Ni3Fe each other. Moreover, the 350 degrees C reduction causes the formation of NiFeOx, accompanied by vanishment of the NiFe(OH)(x). Ethanol electrooxidation is carried out for evaluating the electrocatalytic performance of these samples. The electrocatalytic activity of NiFe-LDH precursor is enhanced by controlling H-2 reduction at 250 degrees C. The high electrical conductivity, created by Ni3Fe metal alloy, is proposed to result in the high electrocatalytic activity of the Ni3Fe/Ni3Fe(OH)(x) heterostructure.