We investigate the delocalization and conductance quantization in finite one-dimensional chains with only off-diagonal disorder coupled to leads. It is shown that the appearance of delocalized states at the middle of the band under correlated disorder is strongly dependent upon the even-odd parity of the number of sites in the system. In samples with inversion symmetry the conductance equals 2e 2 /h for odd samples and is smaller for even parity. This result suggests that this even-odd behavior found previously in the presence of electron correlations may be unrelated to charging effects in the sample.

Pyridinium has been shown to be a cocatalyst for the electrochemical reduction of CO 2 on metal and semiconductor electrodes, but its exact role has been difficult to elucidate. In this work, we create cooperative cobaltprotoporphyrin (CoPP) and pyridine/pyridinium (py/pyH + ) catalytic sites on metal−organic layers (MOLs) for an electrocatalytic CO 2 reduction reaction (CO 2 RR). Constructed from [Hf 6 (μ 3 -O) 4 (μ 3 -OH) 4 (HCO 2 ) 6 ] secondary building units (SBUs) and terpyridine-based tricarboxylate ligands, the MOL was postsynthetically functionalized with CoPP via carboxylate exchange with formate capping groups. The CoPP group and the pyridinium (pyH + ) moiety on the MOL coactivate CO 2 by forming the [pyH + -− O 2 C-CoPP] adduct, which enhances the CO 2 RR and suppresses hydrogen evolution to afford a high CO/ H 2 selectivity of 11.8. Cooperative stabilization of the [pyH + -− O 2 C-CoPP] intermediate led to a catalytic current density of 1314 mA/mgCo for CO production at −0.86 V RHE , which corresponds to a turnover frequency of 0.4 s −1 .

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