Electrocatalytic CO₂ Reduction to Formate on Cu Based Surface Alloys with Enhanced Selectivity

Abstract

Cu is a catalyst that can electrochemically reduce CO 2 to a variety of industrially important carbon products, but often with poor selectivity and low current density. Alloying Cu with other metals provides a useful strategy to tune product selectivity. In this study, four different metal hydroxides were deposited onto Cu(OH) 2 sub-micronsized rods (SMRs) that were grown on a copper foam by an inexpensive and facile method. This procedure was followed by dehydration to form MO x (M = Cd, Sb, Pb, Zn) on a Cu y O SMR surface and then electrochemically reduced to form MCu on the Cu SMR surface. Use of these materials for CO 2 reduction achieves enhancement in formate selectivity in the order of Cd > Sb > Pb > Zn with excellent current density (∼30 mA cm −2 ). The role of the four materials in tuning the selectivity toward formate during electrochemical CO 2 reduction on these modified Cu SMRs is elucidated.

Enabling storage and utilization of low-carbon electricity: power to formic acid

“…38e). 250 Under bulk electrolysis (BE) conditions in the presence of CO2, CdCu@Cu exhibited the highest selectivity towards formate production with an FE of 70.5% and a PCD of 30.5 mA/cm 2 , while ZnCu@Cu and PbCu@Cu only showed moderate selectivity with SbCu@Cu being the least. Irrespective of the composition, all alloyed structures were stable over a 12 h of BE experiments.…”

“…249 (e) Graphic illustration for the synthetic procedure of Cu-M (M = Cd, Zn, Pb, Sb) alloys from their hydroxide precursors on Cu-foam electrode and elctrocatalytic FA production. 250 Besides single metal materials, the use of alloys is often found to be very effective in enhancing both the activity and selectivity for eCO2RR to FA. A significant amount of evidence supports that the combination of different types of metals can favorably control the surface chemical environment and relative binding energy with different intermediates, ultimately producing products that could not be achieved by either metal alone.…”

Recent Advances in Bimetallic Cu‐Based Nanocrystals for Electrocatalytic CO2 Conversion

“…Mosali et al. prepared four kinds of MCu (M=Cd, Zn, Pb, and Sb) alloy nanocrystals on Cu submicron‐size rods (SMRs) through electroreduction of M(OH) x and applied them to CO 2 RR [45] . It turned out that these catalysts all facilitated the selectivity for formate, following the order CdCu/Cu>SbCu/Cu>PbCu/Cu>ZnCu/Cu.…”

CuS Nanosheet Arrays for Electrochemical CO2 Reduction with Surface Reconstruction and the Effect on Selective Formation of Formate

“…The hydrogen evolution reaction (HER) is the main competitive reaction to the electrochemical reaction of CO 2 reduction. 5,6 Meanwhile, multiple products and intermediates are produced during CO 2 reduction through a multiple number of proton-coupled electron transfer steps, resulting in a low selectivity of products. 7,8 In addition, the CO 2 molecule is highly thermodynamically stable and kinetically impeditive, causing an inactivated CO 2 molecule.…”

“…However, some challenges to the electrochemical reaction still exist. The hydrogen evolution reaction (HER) is the main competitive reaction to the electrochemical reaction of CO 2 reduction. , Meanwhile, multiple products and intermediates are produced during CO 2 reduction through a multiple number of proton-coupled electron transfer steps, resulting in a low selectivity of products. , In addition, the CO 2 molecule is highly thermodynamically stable and kinetically impeditive, causing an inactivated CO 2 molecule. , Therefore, the critical need in CO 2 electrocatalytic reduction research is to design and find electrocatalysts that can inhibit the HER, with a low overpotential and effectively promoting the CO 2 reductive reaction, simultaneously, with merits of low cost, high selectivity, high stability, and durability.…”