A Robust One-Compartment Fuel Cell with a Polynuclear Cyanide Complex as a Cathode for Utilizing H2O2 as a Sustainable Fuel at Ambient Conditions

作者：Yamada Yusuke^*; Yoneda Masaki; Fukuzumi Shunichi

来源：Chemistry - A European Journal, 2013, 19(35): 11733-11741.

DOI：10.1002/chem.201300783

• cathodes
• cyanide complexes
• fuel cells
• hydrogen peroxide
• heteropolynuclear complexes

A robust one-compartment H2O2 fuel cell, which operates without membranes at room temperature, has been constructed by using a series of polynuclear cyanide complexes that contain Fe, Co, Mn, and Cr as cathodes, in sharp contrast to conventional H-2 and MeOH fuel cells, which require membranes and high temperatures. A high open-circuit potential of 0.68V was achieved by using Fe-3[{Co-III(CN)(6)}(2)] on a carbon cloth as the cathode and a Ni mesh as the anode of a H2O2 fuel cell by using an aqueous solution of H2O2 (0.30 M, pH3) with a maximum power density of 0.45mWcm(-2). The open-circuit potential and maximum power density of the H2O2 fuel cell were further increased to 0.78V and 1.2mWcm(-2), respectively, by operation under these conditions at pH1. No catalytic activity of Co-3[{Co-III(CN)(6)}(2)] and Co-3[{Fe-III(CN)(6)}(2)] towards H2O2 reduction suggests that the N-bound Fe ions are active species for H2O2 reduction. H2O2 fuel cells that used Fe-3[{Mn-III(CN)(6)}(2)] and Fe-3[{Cr-III(CN)(6)}(2)] as the cathode exhibited lower performance compared with that using Fe-3[{Co-III(CN)(6)}(2)] as a cathode, because ligand isomerization of Fe-3[{M-III(CN)(6)}(2)] into (FeM2)[{Fe-II(CN)(6)}(2)] (M=Cr or Mn) occurred to form inactive FeC bonds under ambient conditions, whereas no ligand isomerization of Fe-3[{Co-III(CN)(6)}(2)] occurred under the same reaction conditions. The importance of stable Fe2+N bonds was further indicated by the high performance of the H2O2 fuel cells with Fe-3[{Ir-III(CN)(6)}(2)] and Fe-3[{Rh-III(CN)(6)}(2)], which also contained stable Fe2+N bonds. The stable Fe2+N bonds in Fe-3[{Co-III(CN)(6)}(2)], which lead to high activity for the electrocatalytic reduction of H2O2, allow Fe-3[{Co-III(CN)(6)}(2)] to act as a superior cathode in one-compartment H2O2 fuel cells.

• 出版日期2013-8-26