Reaction parameters influencing cobalt hydride formation kinetics: Implications for benchmarking H2-evolution catalysts
© 2016 American Chemical Society. 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 pKa, and second-order rate constants is observed for weaker acids. For stronger acids, however, further increases in pKa, do 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.
Publication Source (Journal or Book title)
Journal of the American Chemical Society
Elgrishi, N., Kurtz, D., & Dempsey, J. (2017). Reaction parameters influencing cobalt hydride formation kinetics: Implications for benchmarking H2-evolution catalysts. Journal of the American Chemical Society, 139 (1), 239-244. https://doi.org/10.1021/jacs.6b10148