Fig. 5: Investigation of hydroxyl replenishment.

Quasi in situ XPS spectra of a Cu 2p, b C 1s, and c O 1 s of Cu₃Ni-MA recorded under different conditions. d, e HD evolution during quasi in situ H-D exchange experiment. f H–D isotope exchange DRIFTS of Cu₃Ni-MA recorded under illumination in a CO₂–D₂ atmosphere.