(Invited) Conductive Biopolymers for Selective Metal-Devoid Electrocatalysis

Abstract

Electrocatalysis can be useful in energy conversion, in particular for the production of synthetic fuels from renewable energy. However, this requires catalytic conductors, which sustain the reaction conditions that foremost occur in aqueous solution. Conducting polymers represent a chemically robust but conductive materials class that could be harnessed for aqueous electrocatalytic processes in order to facilitate the important reactions steps to electrosynthesize fuels. In terms of CO2 reduction this has been demonstrated by using a conducting form of polydopamine.(1–3) This system no than other incorporates a richly functionalized backbone able to attach CO2 and electro-reduce to formate efficiently. We shed light on the relevant electro-activation of the incorporated functional themes in the biopolymer and compare this mechanisms to similarly efficient inorganic catalysts. We find that it is the actual nature of the incorporated theme that significantly influences its final selectivity. Such tunability enables the tailoring of selective and highly active catalytic surfaces from organic-functional matter. The functionalzed organic catalysts rely on different reaction mechanisms than state-of-the-art metal-based systems and possibly can be optimized as future sustainable contenders for metal-based electrocatalysts. H. Coskun et al., Chemical vapor deposition - based synthesis of conductive polydopamine thin-films. Thin Solid Films. 645, 320–325 (2018).X. Zheng et al., Sulfur-Modulated Tin Sites Enable Highly Selective Electrochemical Reduction of CO2 to Formate. Joule (2017), doi:10.1016/j.joule.2017.09.014.H. Coskun et al., Biofunctionalized conductive polymers enable efficient CO2 electroreduction. Sci. Adv. 3, e1700686 (2017).