Efficient electrochemical CO2 conversion by cobalt-based metal organic frameworks modified by bimetallic gold-silver nanostructures

The ongoing and rapid growth of atmospheric CO2 levels causes a crucial worldwide concern. Herein, an efficient electrocatalyst has been introduced for electrochemical CO2 reduction reaction (CO2RR) to address the stability issue of ZIF-67. The catalyst consists of gold and silver nanostructures electrodeposited on the surface of a cobalt-based metal-organic framework (Au-Ag@ZIF-67). The uniform distribution of the Au-Ag alloy without any agglomeration on ZIF-67 was confirmed through microscopic observations. After 13.3 h of CO2RR, the specific surface area of Au-Ag@ZIF-67 slightly decreased, whereas that of ZIF-67 declined drastically, indicating excellent structural stability of the Au-Ag alloy. Additionally, Au-Ag@ZIF-67/GCE revealed a faradaic efficiency of 53% and 38% for CO and H-2, respectively. The enhanced CO2 absorption coupled with the effect of noble metal catalysts offered a current density of 16.4 mA cm(-2) at -1 V (vs. RHE) with 91% Faradaic efficiency. The results indicate that ZIF-67 enhanced the adsorption capacity of CO2 molecules in comparison with the bare GCE. The combination of ZIF-67 with bimetallic Au-Ag nanostructures offers enhanced CO2 absorption and reduced charge transfer resistance, leading to improved catalytic activity and selectivity toward CO gas. The results suggest that the use of Au-Ag nanostructures provides superior catalytic activity compared to traditional catalysts, making this approach a promising development for CO2 gas elimination in the environment.

Automated summary

To address the stability issue of ZIF-67, an efficient electrocatalyst consisting of gold and silver nanostructures electrodeposited on a cobalt-based metal-organic framework (Au-Ag@ZIF-67) has been introduced for electrochemical CO2 reduction reaction (CO2RR). The results show that Au-Ag@ZIF-67 exhibits excellent structural stability, enhanced CO2 absorption, and improved catalytic activity towards CO gas, making it a promising development for CO2 gas elimination in the environment.