Multiscale effects in tandem CO₂ electrolysis to C₂₊ products

Abstract

CO2 electrolysis to multicarbon products can be promoted by tandem catalysis. Here we provide an overview of different effects at a range of length scales to identify how catalyst and device design can promote C2+ selectivity.

Low‐Voltage Acidic CO2 Reduction Enabled by a Diaphragm‐Based Electrolyzer

“…[45] There are several reported examples that investigate the temperature effects on the performance of CO 2 R systems. [13,[45][46][47][48][49][50][51][52] However, most of these reports focus mainly on formic acid and carbon monoxide, while neglecting systems forming multicarbon products, or do not conduct analysis in flow cells. Here, we assessed the impact of elevated electrolyte solution temperatures in our system.…”

“…[9] High-rate CO 2 electrolysis can be facilitated using gas-fed flow cells (GFFCs) and membrane electrode assemblies (MEAs). Due to their modularity, many studies have focused on improving the performance (in terms of selectivity, and energy efficiency, among others) by altering components (catalyst, membrane) [10][11][12][13] or conditions (temperature, pressure, pH). [14][15][16] A major development in recent years has been the incorporation of acidic electrolyte solutions in GFFCs that prevent permanent CO 2 loss as (bi)carbonate and can therefore boost the conversion of CO 2 R products.…”

Impact of the Surface Microenvironment on the Redox Properties of a Co-Based Molecular Cathode for Selective Aqueous Electrochemical CO2-to-CO Reduction

“…22,23 Consequently, tandem catalytic systems have emerged to first selectively reduce CO 2 to CO, which is in turn reduced to generate C 2+ products with better selectivity and efficiencies. 24,25 Recent projections have also showed that electrochemical CO production is cost-competitive, approaching the price of fossil-sourced CO. 26 Fully molecular approaches have been explored to generate efficient and selective earth-abundant transition metal catalysts for CO 2 reduction, mainly to CO and HCO 2 − . 27−29 The use of synthetic methods allows for the fine-tuning of molecular designs, which in turn gives access to structure−activity relationships that can lead to further optimizations of the molecular center in terms of activity, stability, and selectivity.…”

“…However, while these processes have been largely improved over the past 5 years, the complexity of the successive reduction steps still leads to mixtures of products, which limit the maturity of these systems. − On the other hand, CO, the simplest of all CO 2 reduction products, is a pivotal building block in the chemical industry ranging from the production of hydrocarbons through the use of Syngas mixtures in Fischer–Tropsch processes or methanol production, , to carbonylation of alkenes (hydroformylation) and alkyl/aryl halides and alcohols . Recent works have also studied the direct electrocatalytic reduction of CO (CORR) to more electron- and proton-rich products using mostly Cu-based catalysts. , Consequently, tandem catalytic systems have emerged to first selectively reduce CO 2 to CO, which is in turn reduced to generate C 2+ products with better selectivity and efficiencies. , Recent projections have also showed that electrochemical CO production is cost-competitive, approaching the price of fossil-sourced CO …”