Dataset Information

Operando Investigation of Ag-Decorated Cu₂ O Nanocube Catalysts with Enhanced CO₂ Electroreduction toward Liquid Products.

ABSTRACT: Direct conversion of carbon dioxide into multicarbon liquid fuels by the CO₂ electrochemical reduction reaction (CO₂ RR) can contribute to the decarbonization of the global economy. Here, well-defined Cu₂ O nanocubes (NCs, 35 nm) uniformly covered with Ag nanoparticles (5 nm) were synthesized. When compared to bare Cu₂ O NCs, the catalyst with 5 at % Ag on Cu₂ O NCs displayed a two-fold increase in the Faradaic efficiency for C₂₊ liquid products (30 % at -1.0 V_RHE ), including ethanol, 1-propanol, and acetaldehyde, while formate and hydrogen were suppressed. Operando X-ray absorption spectroscopy revealed the partial reduction of Cu₂ O during CO₂ RR, accompanied by a reaction-driven redispersion of Ag on the CuO_x NCs. Data from operando surface-enhanced Raman spectroscopy further uncovered significant variations in the CO binding to Cu, which were assigned to Ag-Cu sites formed during CO₂ RR that appear crucial for the C-C coupling and the enhanced yield of liquid products.

SUBMITTER: Herzog A

PROVIDER: S-EPMC8048979 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:To address the challenge of selectivity toward single products in Cu-catalyzed electrochemical CO2 reduction, one strategy is to incorporate a second metal with the goal of tuning catalytic activity via synergy effects. In particular, catalysts based on Cu modified with post-transition metals (Sn or In) are known to reduce CO2 selectively to either CO or HCOO- depending on their composition. However, it remains unclear exactly which factors induce this switch in reaction pathways and whether these two related bimetal combinations follow similar general structure-activity trends. To investigate these questions systematically, Cu-In and Cu-Sn bimetallic catalysts were synthesized across a range of composition ratios and studied in detail. Compositional and morphological control was achieved via a simple electrochemical synthesis approach. A combination of operando and quasi-in situ spectroscopic techniques, including X-ray photoelectron, X-ray absorption, and Raman spectroscopy, was used to observe the dynamic behaviors of the catalysts' surface structure, composition, speciation, and local environment during CO2 electrolysis. The two systems exhibited similar selectivity dependency on their surface composition. Cu-rich catalysts produce mainly CO, while Cu-poor catalysts were found to mainly produce HCOO-. Despite these similarities, the speciation of Sn and In at the surface differed from each other and was found to be strongly dependent on the applied potential and the catalyst composition. For Cu-rich compositions optimized for CO production (Cu85In15 and Cu85Sn15), indium was present predominantly in the reduced metallic form (In0), whereas tin mainly existed as an oxidized species (Sn2/4+). Meanwhile, for the HCOO--selective compositions (Cu25In75 and Cu40Sn60), the indium exclusively exhibited In0 regardless of the applied potential, while the tin was reduced to metallic (Sn0) only at the most negative applied potential, which corresponds to the best HCOO- selectivity. Furthermore, while Cu40Sn60 enhances HCOO- selectivity by inhibiting H2 evolution, Cu25In75 improves the HCOO- selectivity at the expense of CO production. Due to these differences, we contend that identical mechanisms cannot be used to explain the behavior of these two bimetallic systems (Cu-In and Cu-Sn). Operando surface-enhanced Raman spectroscopy measurements provide direct evidence of the local alkalization and its impact on the dynamic transformation of oxidized Cu surface species (Cu2O/CuO) into a mixture of Cu(OH)2 and basic Cu carbonates [Cux(OH)y(CO3)y] rather than metallic Cu under CO2 electrolysis. This study provides unique insights into the origin of the switch in selectivity between CO and HCOO- pathways at Cu bimetallic catalysts and the nature of surface-active sites and key intermediates for both pathways.

Dataset Information

Operando Investigation of Ag-Decorated Cu₂ O Nanocube Catalysts with Enhanced CO₂ Electroreduction toward Liquid Products.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Dataset Information

Operando Investigation of Ag-Decorated Cu2 O Nanocube Catalysts with Enhanced CO2 Electroreduction toward Liquid Products.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Operando Investigation of Ag-Decorated Cu₂ O Nanocube Catalysts with Enhanced CO₂ Electroreduction toward Liquid Products.