Bismuth Metal Porphyrin Framework Doped RuO2 Derived Bi2O3-RuO2@C Composites for Highly Selective CO2 Electroreduction

Abstract

In electrochemical reduction of carbon dioxide (CO2RR), the design of electrocatalysts with high efficiency and selectivity is very important and challenging. In this paper, a ternary composite consisting of ruthenium dioxide and bismuth metal porphyrin-based organic framework (Bi-TCPP MOF)-derived bismuth trioxide and C skeleton has been proposed (denoted as Bi2O3-RuO2@C). Nanoscale RuO2 and Bi2O3 particles are uniformly distributed on the C skeleton. The precursor bismuth metal porphyrin-based organic framework restricts the localized growth of Bi2O3 in the framework, while the unique, highly-conjugated system anchors the doped RuO2 particles, resulting in a uniform distribution of both active sites and hole-enrichment centers. Meanwhile, the Bi-TCPP MOF-derived carbon skeleton has good electrical conductivity, and the macroporous structure also facilitates the gas transport, which leads to the synthesis of Bi2O3-RuO2@C as an electrocatalyst for CO2RR and exhibits excellent catalytic performance and high selectivity for electrocatalytic carbon dioxide reduction to methane (CO2-CH4). The peak Faraday efficiency of Bi2O3-RuO2@C for catalyzing the reduction of CO2-CH4 can reach 66.95% when the doped RuO2 content is 20%. Importantly, this work opens up new horizons for metal ratio regulation in constructing efficient catalytic systems derived from MOFs.