Carbon dioxide (CO2) conversion is promising in alleviating the excessive CO2 level and simultaneously producing valuables. This work reports the preparation of carbon nanorods encapsulated bismuth oxides for the efficient CO2 electroconversion toward formate production. This resultant catalyst exhibits a small onset potential of −0.28 V vs. RHE and partial current density of over 200 mA cm−2 with a stable and high Faradaic efficiency of 93 % for formate generation in a flow cell configuration. Electrochemical results demonstrate the synergistic effect in the Bi2O3@C promotes the rapid and selective CO2 reduction in which the Bi2O3 is beneficial for improving the reaction kinetics and formate selectivity, while the carbon matrix would be helpful for enhancing the activity and current density of formate production. This work provides effective bismuth‐based MOF derivatives for efficient formate production and offers insights in promoting practical CO2 conversion technology.

Electrochemical conversion of carbon dioxide (CO 2 ) into high-value chemical products has become a dramatic research area because of the efficient exploitation of carbon resources and simultaneous reduction of atmospheric CO 2 concentration. Herein, we report the bismuth-based catalyst in the efficient electroconversion of CO 2 for the formation of formate with a maximum Faradaic efficiency of 91% and partial current density of ∼8 mA cm −2 at −0.9 V vs RHE. Experimental and theoretical results show that the bismuth−oxygen structure of bismuth oxides is beneficial for a higher adsorption of CO 2 and the ratedetermining route switching from the initial fast pre-equilibrium of electron transfer process to the subsequent hydrogenation step, accompanied by a lower free energy of intermediate. This work may offer valuable insights into crystal structure engineering to achieve efficient electrocatalysts for selective CO 2 reduction toward generation of valuable products.

Developing an efficient catalyst for the electrocatalytic CO 2 reduction reaction (CO 2 RR) is highly desired because of environmental and energy issues. Herein, we report a single-atomic-site Cu catalyst supported by a Lewis acid for electrocatalytic CO 2 reduction to CH 4 . Theoretical calculations suggested that Lewis acid sites in metal oxides (e.g., Al 2 O 3 , Cr 2 O 3 ) can regulate the electronic structure of Cu atoms by optimizing intermediate absorption to promote CO 2 methanation. Based on these theoretical results, ultrathin porous Al 2 O 3 with enriched Lewis acid sites was explored as an anchor for Cu single atoms; this modification achieved a faradaic efficiency (FE) of 62% at −1.2 V (vs RHE) with a corresponding current density of 153.0 mA cm −2 for CH 4 formation. This work demonstrates an effective strategy for tailoring the electronic structure of Cu single atoms for the highly efficient reduction of CO 2 into CH 4 . KEYWORDS: CO 2 RR, Lewis acid, Al 2 O 3 , single-atom Cu catalyst, CH 4