FeN₄OC Nanoplates Covalently Bonding on Graphene for Efficient CO₂ Electroreduction and ZnCO₂ Batteries

Abstract

Electrochemical carbon dioxide (CO2) reduction into value‐added products holds great promise in moving toward carbon neutrality but remains a grand challenge due to lack of efficient electrocatalysts. Herein, the nucleophilic substitution reaction is elaborately harnessed to synthesize carbon nanoplates with a FeN4O configuration anchored onto graphene substrate (FeN4OC/Gr) through covalent linkages. Density functional theory calculations demonstrate the unique configuration of FeN4O with one oxygen (O) atom in the axial direction not only suppresses the competing hydrogen evolution reaction, but also facilitates the desorption of *CO intermediate compared with the commonly planar single‐atomic Fe sites. The FeN4OC/Gr shows excellent performance in the electroreduction of CO2 into carbon monoxide (CO) with an impressive Faradaic efficiency of 98.3% at −0.7 V versus reversible hydrogen electrode (RHE) and a high turnover frequency of 3511 h−1. Furthermore, as a cathode catalyst in an aqueous zinc (Zn)‐CO2 battery, the FeN4OC/Gr achieves a high CO Faradaic efficiency (≈91%) at a discharge current density of 3 mA cm−2 and long‐term stability over 74 h. This work opens up a new route to simultaneously modulate the geometric and electronic structure of single‐atomic catalysts toward efficient CO2 conversion.

Red blood cell (RBC)-like Ni@N–C composites for efficient electrochemical CO2 reduction and Zn–CO2 batteries

“…5b). 46,47 Impressively, the Ni@NC-950 cathode achieved a peak power density of 2.36 mW cm −2 at a current density of 10.97 mA cm −2 , on par with the best performance of recently reported Zn–CO 2 batteries (refer to Table S2, ESI† for detailed comparisons). Nevertheless, the discharge current density in the Zn–CO 2 battery is significantly lower compared to the current density of eCO 2 RR in the flow cell, similar to existing literature.…”

Unlock flow-type reversible aqueous Zn–CO2 batteries

“…These results provide evidence for the advantageous properties of Pd/SnO 2 @C. In addition to Tafel analysis and EIS, the electrochemically active surface areas (ECSA) of the electrodes, calculated from the double-layer capacitance ( C dl ), are also used to assess the active area of materials. 33 Pd/SnO 2 @C exhibits the highest C dl value of 3.7 mF cm −2 compared to SnO 2 @C (1.02 mF cm −2 ) and Pd@C (3.25 mF cm −2 ). The larger active area of Pd/SnO 2 @C facilitates the adsorption and activation of carbon dioxide, thereby enhancing its eCO 2 RR performance (Fig.…”

Recent progress in nickel single-atom catalysts for the electroreduction of CO2 to CO

“…Among the multiple reduction products, CO is regarded as having the highest market value as it is a crucial feedstock for the Fischer-Tropsch process, which can synthesize highvalue long-chain hydrocarbons. 17 Moreover, because CO is a gaseous product, the complicated and expensive posttreatment procedure of gas-liquid separation is avoided. In recent years, transition metals (Fe, Co and Ni) with unique electronic structures and abundant sources have attracted a lot of attention.…”