Atomically Dispersed Fe-Co Bimetallic Catalysts for the Promoted Electroreduction of Carbon Dioxide

Abstract

The electroreduction reaction of CO2 (ECO2RR) requires high-performance catalysts to convert CO2 into useful chemicals. Transition metal-based atomically dispersed catalysts are promising for the high selectivity and activity in ECO2RR. This work presents a series of atomically dispersed Co, Fe bimetallic catalysts by carbonizing the Fe-introduced Co-zeolitic-imidazolate-framework (C–Fe–Co–ZIF) for the syngas generation from ECO2RR. The synergistic effect of the bimetallic catalyst promotes CO production. Compared to the pure C–Co–ZIF, C–Fe–Co–ZIF facilitates CO production with a CO Faradaic efficiency (FE) boost of 10%, with optimal FECO of 51.9%, FEH2 of 42.4% at − 0.55 V, and CO current density of 8.0 mA cm−2 at − 0.7 V versus reversible hydrogen electrode (RHE). The H2/CO ratio is tunable from 0.8 to 4.2 in a wide potential window of − 0.35 to − 0.8 V versus RHE. The total FECO+H2 maintains as high as 93% over 10 h. The proper adding amount of Fe could increase the number of active sites and create mild distortions for the nanoscopic environments of Co and Fe, which is essential for the enhancement of the CO production in ECO2RR. The positive impacts of Cu–Co and Ni–Co bimetallic catalysts demonstrate the versatility and potential application of the bimetallic strategy for ECO2RR.

The Deep Understanding into the Promoted Carbon Dioxide Electroreduction of ZIF‐8‐Derived Single‐Atom Catalysts by the Simple Grinding Process

“…All these XAS results confirm that the grinding process affects the local chemical environments of the Co atoms of C–Co–ZIF samples, which can contribute to the enhancement of the ECO 2 RR performance. [ 24 ]…”

“…All these XAS results confirm that the grinding process affects the local chemical environments of the Co atoms of C-Co-ZIF samples, which can contribute to the enhancement of the ECO 2 RR performance. [24] If Co-N 4 is assumed to be the active site in the catalysts, the number of the total active sites can be calculated to evaluate the turnover frequency (TOF) of the catalysts. The TOF results of CO production calculated at À0.…”

“…Our group has previously worked on Co‐based ZIF‐8 (Co‐ZIF)‐derived SACs in ECO 2 RR. [ 24 ] Hence, we continue to choose Co‐ZIF to conduct the investigation of the impact of the grinding process in the synthesis of ZIF‐8‐derived SACs for ECO 2 RR.…”

“…In this work, we prepared the Co‐ZIF‐derived SACs as illustrated in our previous work. [ 24 ] Combining with different grinding processes such as hand milling and ball milling to create different degrees of the ground Co SACs (hand milling and ball milling for the moderate and intense grinding degrees, respectively), the catalysts were tested in ECO 2 RR. The original Co SAC (C–Co–ZIF) that is without any grinding process exhibits FEco of around 45% and FE H2 of around 50% at −0.55 V versus reversible hydrogen electrode (RHE) and a CO current density of around 5 mA cm −2 at −0.7 V versus RHE.…”

Recent Advances in Dual‐Atom Site Catalysts for Efficient Oxygen and Carbon Dioxide Electrocatalysis

“…X‐ray photoelectron spectroscopy illustrated that appropriate Fe doping can increase the number of M‐N sites and improve the performance. [ 110 ] In order to understand the neighboring effect between monomers, Zn‐Co DAC was investigated. EXAFS and XANES spectra collectively proved that there was no metal‐metal bonding between Zn and Co, but an electronic effect.…”