Sub-100 mA/cm2 CO2-to-CO Reduction Current Densities in Hierarchical Porous Gold Electrocatalysts Made by Direct Ink Writing and Dealloying.
ACS Appl Mater Interfaces
; 15(23): 27905-27914, 2023 Jun 14.
Article
en En
| MEDLINE
| ID: mdl-37276347
ABSTRACT
While most research efforts on CO2-to-CO reduction electrocatalysts focus on boosting their selectivity, the reduction rate, directly proportional to the reduction current density, is another critical parameter to be considered in practical applications. This is because mass transport associated with the diffusion of reactant/product species becomes a major concern at a high reduction rate. Nanostructured Au is a promising CO2-to-CO reduction electrocatalyst for its very high selectivity. However, the CO2-to-CO reduction current density commonly achieved in conventional nanostructured Au electrocatalysts is relatively low (in the range of 1-10 mA/cm2) for practical applications. In this work, we combine direct ink writing-based additive manufacturing and dealloying to design a robust hierarchical porous Au electrocatalyst to improve the mass transport and achieve high CO2-to-CO reduction current densities on the order of 64.9 mA/cm2 with CO partial current density of 33.8 mA/cm2 at 0.55 V overpotential using an H-cell configuration. Although the current density achieved in our robust hierarchical porous Au electrocatalyst is one order of magnitude higher than the one achieved in conventional nanostructured electrocatalysts, we found that the selectivity of our system is relatively low, namely 52%, which suggests that mass transport remains a critical issue despite the hierarchical porous architecture. We further show that the bulk dimension of our electrocatalyst is a critical parameter governing the interplay between selectivity and reduction rate. The insights gained in this work shed new light on the design of electrocatalysts toward scale-up CO2 reduction and beyond.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
ACS Appl Mater Interfaces
Asunto de la revista:
BIOTECNOLOGIA
/
ENGENHARIA BIOMEDICA
Año:
2023
Tipo del documento:
Article
País de afiliación:
Estados Unidos