X-ray absorption spectroscopy experiments were performed at the Advanced Photon Source (APS), Argonne National Laboratory in Lemont, Illinois, in sector 10 MR-CAT (Materials Research Collaborative Access Team). The insertion device beamline at sector 10 (10-ID) was used for in situ experiments. A Cu metal foil reference spectrum (edge energy of 8979 eV) was measured simultaneously with each sample spectrum collected to calibrate the X-ray beam for spectral measurements at the Cu K-edge. All sample spectra were analyzed in WinXAS and normalized using first and third order polynomials for background subtraction of the pre-and post-edges, respectively. The standards used for linear combination fitting (LCF) of the XANES spectra were Cu-CHA dehydrated in 21 kPa O2 (balance He) at 723 K and Cu2O (Sigma Aldrich), for Cu(II) and Cu(I), respectively, as shown in Figure .