Mechanisms of multielectron catalysis in enzymes and surfaces

4 problems

• First-principles prediction of absolute catalytic turnover frequencies

  Open

  Computer models can rank catalysts by trends, but they rarely predict the actual speed of a catalytic reaction. Small errors in computed energies change the predicted speed enormously.

• Active site of copper-zinc methanol synthesis catalysts

  Contested

  Most of the world's methanol is made from carbon oxides and hydrogen over copper particles mixed with zinc oxide. Whether the reaction runs on copper steps decorated with zinc, on a copper-zinc surface alloy, or at the boundary with zinc oxide is still argued.

• Where and how nitrogen binds to the nitrogenase cofactor

  Open

  Nitrogenase must add four electrons and protons to its metal cluster before nitrogen gas can bind and be broken. Which metal atom grabs the nitrogen and what the cluster looks like at that moment are uncertain.

• How the O-O bond forms in photosystem II

  Partially resolved

  Plants split water using a cluster of four manganese atoms and one calcium atom. The step where two oxygen atoms join to make $\mathrm{O_2}$ has not been directly seen.