Atomic Indium Catalysts for Switching CO₂ Electroreduction Products from Formate to CO

Abstract

Electrochemical reduction of CO 2 to chemicals and fuels is an interesting and attractive way to mitigate greenhouse gas emissions and energy shortages. In this work, we report the use of atomic In catalysts for CO 2 electroreduction to CO. The atomic In catalysts were anchored on N-doped carbon (In A /NC) through pyrolysis of In-based metal−organic frameworks (MOFs) and dicyandiamide. It was discovered that In A /NC had outstanding performance for selective CO production in the mixed electrolyte of ionic liquid/ MeCN. It is different from those common In-based materials, in which formate/ formic acid is formed as the main product. The faradaic efficiency (FE) of CO and total current density were 97.2% and 39.4 mA cm -2 , respectively, with a turnover frequency (TOF) of ∼40 000 h −1 . It is one of the highest TOF for CO production to date for all of the catalysts reported. In addition, the catalyst had remarkable stability. Detailed study indicated that In A /NC had higher double-layer capacitance, larger CO 2 adsorption capacity, and lower interfacial charge transfer resistance, leading to high activity for CO 2 reduction. Control experiments and theoretical calculations showed that the In−N site of In A /NC is not only beneficial for dissociation of COOH* to form CO but also hinders formate formation, leading to high selectivity toward CO instead of formate.

Highly Efficient CO2 Electroreduction to Methanol through Atomically Dispersed Sn Coupled with Defective CuO Catalysts

“…[22] Their atomically distributed active sites can present excellent selectivity and maximum atom efficiency.T od ate,m any efforts have been devoted to developing SASCs for CO 2 electroreduction. [23][24][25][26][27][28] Nevertheless,s of ar majority of SASCs applied in CO 2 electroreduction just produce CO through 2-electron transfer. Multi-electron reduction to generate high value-added products has been rarely reported.…”

Surface Oxygen Injection in Tin Disulfide Nanosheets for Efficient CO2 Electroreduction to Formate and Syngas

“…Given that the CO 2 molecule activation is closely related to the number and inherent activity of active sites, many effective strategies have been employed to tailor the active sites of electrocatalysts for enhancing the efficiency of the CO 2 electroreduction to formate [19][20][21]. The surface chemistry modification, as a powerful strategy, has attracted great interest in adjusting electronic properties of active sites to target intermediate adsorption energy as well as harvest high selectivity [22][23][24][25].…”

Understanding Single-Atom Catalysis in View of Theory

“… 41 Thus, kinetic analysis should be included to explain the preferential production of the C 1 product and the inhibition of HER as discussed in section 3.4 . Furthermore, if Δ G HCOO* is lower than Δ G *COOH and the free energy of the potential-determining step for formate is higher than that of the formation of CO, 98 CO was suggested as the dominant product. However, the lower energy of HCOO* would make the active sites unavailable for *COOH, which may contradict previous discussion in the selectivity.…”