Enhancing the CO₂-to-CO Conversion from 2D Silver Nanoprisms via Superstructure Assembly

Abstract

The electrochemical reduction of CO2 in a highly selective and efficient manner is a crucial step towards its reuse for the production of chemicals and fuels. Nanostructured Ag catalysts have been found to be effective candidates for the conversion of CO2 to CO. However, the ambiguous determination of the intrinsic CO2 activity and the maximization of the density of exposed active sites has greatly limited the use of Ag towards the realization of practical electrocatalytic devices.Here, we report a superstructure design strategy prepared by the self-assembly of two-dimensional Ag nanoprisms for maximizing the exposure of active edge ribs. The vertically stacked Ag nanoprisms allow exposure of > 95% of the edge sites, resulting in an enhanced selectivity and activity towards the production of CO from CO2 with an overpotential of 152 mV. The Ag superstructures also demonstrates a selectivity over 90% for 100 hours together with a current retention of ≈ 94% at -600 mV versus the reversible hydrogen electrode and a partial energy efficiency for CO production of 70.5%. Our electrochemical measurements on individual Ag nanoprisms with various edge-to-basal plane ratios and the Ag superstructures led to the identification of the edge ribs as the active sites thanks to the ≈ 400 mV decrease in the onset potential compared to that of the Ag (111) basal planes and a turnover frequency of 9.2 × 10 -3 ± 1.9 × 10 -3 s -1 at 0 V overpotential.

Tubular Catalytic Polyhipe Reactor with Deposited Silver Nanoplate Nanoparticles

“…This demonstrates the superiority of silver nanoplates in their catalytic activity, which was expected due to their low sphericity factor. However, the such large difference must also be attributed to higher reactivity, probably caused by the reactive twinned planes and stacking faults [36,68,94]. Comparison with some literature results where the same reaction for AgNP catalytic activity was investigated shows that the obtained value is one of the highest reported (Table 1).…”

“…Furthermore, due to high surface to volume ratio and low sphericity factor they are also promising candidate for an efficient catalyst [3]. In addition to attractive morphology, their twin planes are combined with multiple stacking faults [67], causing high reactivity of those planes, resulting in high catalytic activity [68]. In practice it is difficult to determine the catalytic activity of colored AgNP colloids in batch reactors, because their UV-Vis absorbance spectrum can overlap with that of model dyes such as 4-nitrophenol (4-NP), which are commonly converted to study the catalytic activity of metal nanoparticles, including nanoplates [69,70].…”

Bi2O3 Nanosheets Grown on Carbon Nanofiber with Inherent Hydrophobicity for High-Performance CO2 Electroreduction in a Wide Potential Window

“…Moreover, most prior studies mainly focused on enhancing the production of C 2+ products over Cu-based materials by surface hydrophobic engineering. Although most C 1 -producing catalysts (such as Pd, Ag, Bi, In, and Sn) have achieved high selectivity for C 1 products (formate or CO), − their formation rates still fall below the commercial requirement because it is difficult to attain high j in the presence of competing HER and the CO 2 mass transport limitation in aqueous medium. Benefiting from the hydrophobic microenvironment, the developed Bi 2 O 3 @C/HB catalyst in this study exhibits high selectivity at a high j for CER toward formate production, thereby achieving a high formate formation rate.…”

Water-Dispersible CsPbBr3 Perovskite Nanocrystals with Ultra-Stability and its Application in Electrochemical CO2 Reduction

“…Electrochemical or photochemical reduction of carbon dioxide (CO 2 ) could efficiently recycle the greenhouse gas back to fuels [1][2][3]. However, the existing perovskite catalysts are either inefficient or unstable.…”