Organic molecules as mediators and catalysts for photocatalytic and electrocatalytic CO2 reduction

Chem Soc Rev. 2013 Mar 21;42(6):2253-61. doi: 10.1039/c2cs35276a. Epub 2012 Sep 20.

Abstract

Reduction of CO(2) by electrochemical and photoelectrochemical methods to produce carbon-rich fuels is a heavily pursued research theme. Most of the current efforts are focused on the development of transition-metal-based catalysts. In this tutorial review, we present an overview of the development of organic molecules as mediators and catalysts for CO(2) reduction. Four classes of organic molecules are discussed: tetraalkylammonium salts, aromatic esters and nitriles, ionic liquids, and pyridinium derivatives. It is shown that reactions mediated or catalyzed by these organic molecules can be competitive compared to their metal-catalyzed counterparts, both in terms of product selectivity and energy efficiency.