title: Reaction Parameters Influencing Cobalt Hydride Formation Kinetics: Implications for Benchmarking H(2)-Evolution Catalysts.
abstract: The need for benchmarking hydrogen evolution catalysts has increasingly been recognized. The influence of acid choice on activity is often reduced to the overpotential for catalysis. Through the study of a stable cobalt hydride complex, we demonstrate the influence of acid choice, beyond pKa, on the kinetics of hydride formation. A linear free energy relationship between acid pKaand second-order rate constants is observed for weaker acids. For stronger acids, however, further increases in pKado not correlate to increases in rate constants. Further, steric bulk around the acidic proton is shown to influence rate constants dramatically. Together, these observations reveal the complex factors dictating catalyst performance.
authors.affiliation: Department of Chemistry, University of North Carolina , Chapel Hill, North Carolina 27599-3290, United States.
authors.forename: Noémie
authors.identifier: 0000-0001-9776-5031
authors.initials: N
authors.lastname: Elgrishi
authors.affiliation: Department of Chemistry, University of North Carolina , Chapel Hill, North Carolina 27599-3290, United States.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Kurtz
authors.affiliation: Department of Chemistry, University of North Carolina , Chapel Hill, North Carolina 27599-3290, United States.
authors.forename: Jillian L
authors.identifier: 0000-0002-9459-4166
authors.initials: JL
authors.lastname: Dempsey