Increasing the rate of hydrogen oxidation without increasing the overpotential [electronic resource] : A bio-inspired iron molecular electrocatalyst with an outer coordination sphere proton relay

• Ngôn ngữ: eng
• Ký hiệu phân loại: 541.3 Miscellaneous topics in physical chemistry
• Thông tin xuất bản: Richland, Wash. : Oak Ridge, Tenn. : Pacific Northwest National Laboratory (U.S.) ; Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2015
• Mô tả vật lý: Size: p. 2737-2745 : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 255855
• Chủ đề: 1. 30 direct energy conversion; 2. 37 inorganic, organic, physical, and analytical chemistry; 3. Diphosphine; 4. Homogeneous catalysis; 5. Hydrogen oxidation; 6. Iron; 7. Outer coordination sphere; 8. Proton transport

Tóm tắt

 Oxidation of hydrogen (H?) to protons and electrons for energy production in fuel cells is catalyzed by platinum, but its low abundance and high cost present drawbacks to widespread adoption. Precisely controlled proton delivery and removal is critical in hydrogenase enzymes in nature that catalyze H? oxidation using earth-abundant metals (iron and nickel). Here we report a synthetic iron complex, (Cp<
 sup>
 C<
 sub>
 5<
 /sub>
 F<
 sub>
 4<
 /sub>
 N<
 /sup>
 )Fe(P<
 sup>
 Et<
 /sup>
 N<
 sup>
 (CH<
 sub>
 2<
 /sub>
 )<
 sub>
 3<
 /sub>
 NMe<
 sub>
 2<
 /sub>
 <
 /sup>
 PEt)(Cl), that serves as a precatalyst for the oxidation of H?, with turnover frequencies of 290 s?� in fluorobenzene, under 1 atm of H? using 1,4-diazabicyclo[2.2.2]octane (DABCO) as the exogenous base. The cooperative effect of the primary, secondary and outer coordination spheres for moving protons in this remarkably fast catalyst emphasizes the key role of pendant amines in mimicking the functionality of the proton pathway in the hydrogenase enzymes.