Intermediate Binding Control Using Metal-Organic Frameworks Enhances Electrochemical CO Reduction.

In the electrochemical CO reduction reaction (CORR), control over the binding of intermediates is key for tuning product selectivity and catalytic activity. Here we report the use of reticular chemistry to control the binding of CORR intermediates on metal catalysts encapsulated inside metal-organic frameworks (MOFs), thereby allowing us to improve CORR electrocatalysis. By varying systematically both the organic linker and the metal node in a face-centered cubic () MOF, we tune the adsorption of CO, pore openness, and Lewis acidity of the MOFs. Using X-ray absorption spectroscopy (XAS) and Raman spectroscopy, we reveal that the MOFs are stable under operating conditions and that this tuning plays the role of optimizing the *CO binding mode on the surface of Ag nanoparticles incorporated inside the MOFs with the increase of local CO concentration. As a result, we improve the CO selectivity from 74% for Ag/Zr--MOF-1,4-benzenedicarboxylic acid (BDC) to 94% for Ag/Zr--MOF-1,4-naphthalenedicarboxylic acid (NDC). The work offers a further avenue to utilize MOFs in the pursuit of materials design for CORR.