Interface-Rich Highly Oxophilic Copper/Tin–Oxide Nanocomposite on Reduced Graphene Oxide for Efficient Electroreduction of CO₂ to Formate

Abstract

In recent days, it has been reported that bimetallic electrocatalysts can increase the activity for electrochemical formate (HCOO − ) production during CO 2 reduction. However, they still have some apparent drawbacks such as poor selectivity and durability. In the current work, notable improvements in the electrochemical CO 2 reduction (CO 2 RR) to formate production were accomplished by incorporation of reduced graphene oxide (rGO) into nanostructured bimetallic CuSnO x electrocatalysts (Cu x SnO x /rGO). The interface-rich mixed crystalline−amorphous nanostructured Cu 0.33 SnO x /rGO nanocomposite is able to enhance the electrocatalytical activity, resulting in conversion of CO 2 to formate with lower overpotential of 590 mV vs RHE. The control experiments show that the presence of SnO x in the catalyst considerably increased electrocatalytic activity and product selectivity toward formate production. Further, the increased oxophilicity of the Cu 0.33 SnO x /rGO nanocomposite supports the plausible CO 2 reduction mechanism through the formation of bicarbonate intermediate, as demonstrated by CO stripping studies. The Cu 0.33 SnO x /rGO had maximum formate faradaic efficiency (80.62%) at lower potential of −0.69 V (RHE), which is 2.09 and 1.85 times better than those of CuSnO x /rGO and Cu 3 SnO x /rGO nanocomposites, respectively. The catalytic performance may be attributed to synergistic interaction, the presence of interfaces, higher electrochemical surface area, and the mixed crystalline−amorphous nature of Cu 0.33 SnO x /rGO nanocomposite. Thus, the obtained results gave rise to a practical method for boosting the activity and product selectivity of electrocatalysts for efficient CO 2 conversion.

Catalytic heterostructured materials for CO2 mitigation and conversion into fuels: a renewable energy approach towards a sustainable environment

“…These modifications also proved to be good when discussing their role in photocatalytic CRR. 152 Heterostructure SnO 2− x /g-C 3 N 4 exhibits superior photocatalytic performance towards reduction of CO 2 . These two semiconductors possess suitable positions of the VB and CB as depicted in Fig.…”

Bilayer Porous Electrocatalysts for Stable and Selective Electrochemical Reduction of CO2 to Formate in the Presence of Flue Gas Containing NO and SO2

“…According to several studies, the formic acid selectivity can be enhanced during CO 2 reduction by modifying the electrocatalysts to metal oxides, , nanostructures, − porous structures, − bimetallic alloys, , metals combined with carbon materials, − and heteroatom-doped catalysts. − Among these, porous metal foam structures are considered promising electrocatalysts because of their hierarchical open-pore structures, which offer many exposed active sites, good mass transfer capacity, and great potential for electrochemical applications . Researchers have studied different metal foam structures on substrates made of foil and mesh, including Cu, Sn, In, and Zn. − Among these, Cu is a viable metal because of its low cost and high electrical conductivity, and it is the only single metal that can facilitate the electrochemical conversion of CO 2 to hydrocarbons due to its intermediate binding strength to *CO and the high surface adsorption coverage, allowing to generate a variety of products .…”

Unveil the Potential-Dependent Electrochemical Formate Formation on Topological PtBi2 Monolayer

“…1−23 Among the various reduced hydrocarbons, formic acid has garnered considerable interest. 4,5 Formic acid serves as both a direct fuel source for formic acid fuel cells 6,7 and a crucial raw material for the production of numerous medical intermediates like formate esters, acridine dyes, and formamides. 8−10 Moreover, formic acid holds potential as a carrier for hydrogen (H 2 ) due to its favorable characteristics such as easy storage and high volumetric hydrogen density.…”

“…Electrochemical reduction of CO 2 (ECR) driven by renewable electricity presents a promising approach for mitigating the greenhouse effect and generating valuable chemicals. − Among the various reduced hydrocarbons, formic acid has garnered considerable interest. , Formic acid serves as both a direct fuel source for formic acid fuel cells , and a crucial raw material for the production of numerous medical intermediates like formate esters, acridine dyes, and formamides. − Moreover, formic acid holds potential as a carrier for hydrogen (H 2 ) due to its favorable characteristics such as easy storage and high volumetric hydrogen density. , The conversion of CO 2 to formic acid offers an exciting prospect for storing intermittent renewable energy and achieving carbon neutrality. − Nevertheless, the electrochemical conversion of CO 2 to formic acid still faces several challenges.…”