Selective electrochemical reduction of CO₂ to formic acid in a gas phase reactor with by-product recirculation

Abstract

Recirculation is a chemical engineering concept generally applied to enhance the conversion of reagents. In common applications, by-products are removed together with the desired products and only the unconverted feed...

The inchoate horizon of electrolyzer designs, membranes and catalysts towards highly efficient electrochemical reduction of CO2 to formic acid

“…Despite a decrease in CO 2 solubility, the PCD of HCOO − enhanced two times with 52.9 mA cm −2 when the reaction temperature increased from 303 to 363 K. Also, an appreciably high HCOO − concentration of 41.5 g L −1 has been observed with a significant PCD (51.7 mA cm −2 ) and high FE (93.3%) at 2.2 V. An improved electrochemical reduction is demonstrated ( Fig. 10a and b ) for Sustainion™ anion exchange membrane with a nanoparticle Sn GDE carrying an imidazole ionomer, which displayed a stable electrochemical cell performance for 500 h at 140 mA cm −2 and at a cell voltage of only 3.5 V. 50 More recently, Thijs et al 51 adopted a novel strategy to enhance the CO 2 R to HCOO − or HCOOH by the recirculation of the by-products to the reactor along with unconverted CO 2 . It has been elaborated that different MEA-type gas and liquid phase reactors ( Fig.…”

“…Among these four configurations, H 2 evolves as the main by-products and the aqueous environment is needed for the proton source against HCOOH formation. In order to avoid the formation of H 2 by-product, a new strategy has been developed by Thijs et al 51 based on type III configuration. A typical gas phase CO 2 R reactor with recirculation has been proposed in Fig.…”

Electroreduction of CO2: Advances in the Continuous Production of Formic Acid and Formate

“…Definitions of the figures of merit are explained in Section . The last column shows the icon used to represent each study in the graphical representations of Figures –, according to the symbols and meanings detailed in Table . …”

“…Pt-based anodes with different physical configurations (Pt-wire, Pt-sheet, Pt-mesh, and Pt-gauze) have been the most used in the continuous electrochemical reduction of CO 2 to HCOOH and HCOO – (Table ). ,, He et al supplied the highest current density (500 mA·cm –2 ) employing Pt-based anodes (Table ). However, despite the high electron conductivity of Pt, its availability and cost are still limiting factors for its implementation on a larger scale …”