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Title: A Cobalt Hydride Catalyst for the Hydrogenation of CO2: Pathways for Catalysis and Deactivation

The complex Co(dmpe)₂H catalyzes the hydrogenation of CO₂ at one atm and 21 ºC with significant improvement in turnover frequency relative to previously reported second and third row transition metal complexes. New studies are presented to elucidate the catalytic mechanism as well as pathways for catalyst deactivation. The catalytic rate was optimized through the choice of the base to match the pKa of the [Co(dmpe)₂(H)₂]⁺ intermediate. By using a strong enough base, the catalytic rate has a zero order dependence on the concentration of base and pressure of hydrogen, and a first order dependence on the pressure of CO₂. However, upon exceeding CO₂:H₂ ratios of greater than one, the catalytically inactive species [(μ-dmpe)(Co(dmpe)₂)₂]²⁺ and [Co(dmpe)₂CO]⁺ are observed. Research by M.S.J., M.T.M., A.M.A., and J.C.L. was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Research by M.L.H. and E.B.H. was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for the DOE by Battelle.
Authors:
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Publication Date:
OSTI Identifier:
1168899
Report Number(s):
PNNL-SA-103938
KC0302010; KC0307010
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: ACS Catalysis, 4(10):3755-3762
Research Org:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
COBALT; HYDROGENATION; CATALYSIS CO2; cobalt; hydrogenation; catalysis