Efficient Electrocatalytic CO2 Reduction to Formate via Continuous Microfluidic Synthesis of Bi2O3/MXene‐Based Composite Catalysts with Tunable Metal Oxide Interfaces

High-loading Bi₂O₃ nanostructures are uniformly anchored onto MXene via microfluidics and thermal treatment, enabling synergistic and efficient CO₂ electroreduction to formate.

Abstract

The large-scale applications of electrocatalytic CO₂ reduction face numerous challenges, including suppressed HER, high catalyst costs, limited production scalability, and complex synthesis processes. Combining carbon materials with bismuth-based catalysts is an effective strategy to enhance catalytic activity at low cost. This study utilized microfluidic technology to achieve mass aggregations of Bi₂O₃ nanoparticles with specific surfaces and controllable size on 2D Mxene using 2, 5-FDCA as a ligand. The In-depth understanding of theoretical simulations indicates the MXene substrate significantly improved the catalyst's electrochemical surface area and electron transport efficiency, facilitating electrolyte penetration and reactant diffusion. While Bi₂O₃ support provided abundant active sites for reactions. Beyond, the composite M-Bi₂O₃/MXene-400 effectively suppress HER through synergistic effects. The interaction between Bi₂O₃ and substrate is greatly increased to stabilize the M-Bi₂O₃/MXene-400 structure under work. In a membrane electrode assembly (MEA), it operate continuously for 60 h at a cell potential of −2.8 V, achieving a current density of −300 mA cm⁻² and an average Faradaic efficiency for formate exceeding 90%. This work offers new strategies for the efficient design and controllable construction of MXene-supported nanoparticle catalysts and mass production via microfluidic technology.