Deformed One-Dimensional Covalent Organic Polymers for Enhanced CO Electroreduction to Methanol.

Abstract

Spatially arranged molecular catalysts in polymeric frameworks, typically in a layered structure, are emerging strategies to mitigate the molecular aggregation and improve the catalytic performance. However, the effect of local coordination induced by polymerization remains underexplored. Here, we develop one-dimensional cobalt-tetra-amino-phthalocyanine-based covalent organic polymers (1D-COP) for the electrochemical CO reduction reaction (CORR). We use carbon nanotubes as ideal templates to induce local curvature of the 1D-COP. The COP on single-walled CNT (1D-COP/SWCNT) catalyst exhibits a maximum methanol Faradaic efficiency of 70% in an H-cell, which exceeds those on wider-diameter multiwalled carbon nanotubes (22% for 4-6 nm and 14% for 10-20 nm). Using X-ray and vibronic spectroscopies, we have observed distinct local geometries and electronic structures induced by the strong interactions between the COP layer and CNT substrates. Density functional theory calculations further support that increased curvature of the COP-SWCNT catalyst enhances the *CO binding species, leading to improved subsequent reduction reactions. Our results highlight the critical role of the local structure in polymeric frameworks for improved electrocatalytic performance.