Electrocatalytic CO2 Reduction: From Homogeneous Catalysts to Heterogeneous-Based Reticular Chemistry

摘要

CO2, emitted mainly from fossil fuel combustion, is one of the major greenhousegases. CO2 could be converted into more valuable chemical feedstocks including CO, HCOOH,HCHO, CH3OH, or CH4. To reduce CO2, catalysts were designed and their unique characteristicswere utilized based on types of reaction processes, including catalytic hydrogenation, complexmetal hydrides, photocatalysis, biological reduction, and electrochemical reduction. Indeed,the electroreduction method has received much consideration lately due to the simple operation, aswell as environmentally friendly procedures that need to be optimized by both of the catalysts andthe electrochemical process. In the past few decades, we have witnessed an explosion in developmentin materials science—especially in regards to the porous crystalline materials based on the strongcovalent bond of the organic linkers containing light elements (Covalent organic frameworks, COFs),as well as the hybrid materials that possess organic backbones and inorganic metal-oxo clusters(Metal-organic frameworks, MOFs). Owing to the large surface area and high active site density thatbelong to these tailorable structures, MOFs and COFs can be applied to many practical applications,such as gas storage and separation, drug release, sensing, and catalysis. Beyond those applications,which have been abundantly studied since the 1990s, CO2 reduction catalyzed by reticular andextended structures of MOFs or COFs has been more recently turned to the next step of state-of-the-artapplication. In this perspective, we highlight the achievement of homogeneous catalysts used for CO2electrochemical conversion and contrast it with the advances in new porous catalyst-based reticularchemistry. We then discuss the role of new catalytic systems designed in light of reticular chemistryin the heterogeneous-catalyzed reduction of CO2.