[Vo]:Inexpensive catalyst makes hydrogen 10 times faster than natural enzyme

[Mark Iverson]

FYI:
 
Inexpensive catalyst that makes hydrogen gas 10 times faster than natural enzyme
http://www.physorg.com/news/2011-08-inexpensive-catalyst-hydrogen-gas-faster.html
Looking to nature for their muse, researchers have used a common protein to 
guide the design of a material that can make energy-storing hydrogen gas. The 
synthetic material works 10 times faster than the original protein found in 
water-dwelling microbes, the researchers report in the August 12 issue of the 
journal Science, clocking in at 100,000 molecules of hydrogen gas every second.
 
http://www.sciencemag.org/content/333/6044/863
Abstract
 
Reduction of acids to molecular hydrogen as a means of storing energy is 
catalyzed by platinum, but its low abundance and high cost are problematic. 
Precisely controlled delivery of protons is critical in hydrogenase enzymes in 
nature that catalyze hydrogen (H2) production using earth-abundant metals (iron 
and nickel). Here, we report that a synthetic nickel complex, 
[Ni(PPh2NPh)2](BF4)2, (PPh2NPh = 
1,3,6-triphenyl-1-aza-3,6-diphosphacycloheptane), catalyzes the production of 
H2 using protonated dimethylformamide as the proton source, with turnover 
frequencies of 33,000 per second (s−1) in dry acetonitrile and 106,000 s−1 in 
the presence of 1.2 M of water, at a potential of –1.13 volt (versus the 
ferrocenium/ferrocene couple). The mechanistic implications of these remarkably 
fast catalysts point to a key role of pendant amines that function as proton 
relays.

-Mark