A fast soluble carbon-free molecular water oxidation catalyst based on abundant metals.
Traditional homogeneous water oxidation catalysts are plagued by instability under the reaction conditions. We report that the complex [Co4(H2O)2(PW9O34)2]10-, comprising a Co4O4 core stabilized by oxidatively resistant polytungstate ligands, is a hydrolytically and oxidatively stable homogeneous water oxidation catalyst that self-assembles in water from salts of earth-abundant elements (Co, W, and P). With [Ru(bpy)3]3+ (bpy is 2,2'-bipyridine) as the oxidant, we observe catalytic turnover frequencies for O2 production > or = 5 s(-1) at pH = 8. The rate's pH sensitivity reflects the pH dependence of the four-electron O2-H2O couple. Extensive spectroscopic, electrochemical, and inhibition studies firmly indicate that [Co4(H2O)2(PW9O34)2]10- is stable under catalytic turnover conditions: Neither hydrated cobalt ions nor cobalt hydroxide/oxide particles form in situ.
Department of Chemistry, Emory University, Atlanta, GA 30322, USA.
Qiushi
Q
Yin
Jeffrey Miles
JM
Tan
Claire
C
Besson
Yurii V
YV
Geletii
Djamaladdin G
DG
Musaev
Aleksey E
AE
Kuznetsov
Zhen
Z
Luo
Ken I
KI
Hardcastle
Craig L
CL
Hill