Rapid screening of copper-based bimetallic catalysts via automatic electrocatalysis platform: Electrocatalytic reduction of CO2 to C2+ products on europium-modified copper

The electrocatalytic conversion of CO₂ (CO₂RR) to multi-carbon products has been an appealing strategy to reduce carbon emissions. However, rapid experimental discovery of efficient CO₂RR electrocatalysts and fast recording of full product distribution information is non-trivial. Herein, we used an electrocatalyst testing platform featuring a home-built automatic flow cell to accelerate catalysts screening. Based on 364 effective data points from 42 Cu-lanthanide bimetallic catalysts obtained within 21 working hours, we found that Eu modification over Cu can promote C₂₊ faradaic efficiency (FE). We have previously reported part of the screening data and the optimization of the Mg-Cu catalyst（Angew. Chem. 2022, 134, e202213423）. Here we augmented the dataset by adding the lanthanide modifiers and reported the Eu-Cu catalyst resulted from the high-throughput investigation. Our characterizations revealed that the Eu²⁺ reduced from Eu³⁺ during the catalyst synthesis prevented the agglomeration of nanoparticles, thus making europium modifications stand out from other lanthanide metal modifiers on FE C₂₊ enhancement. We then optimized the Eu-CuO_x catalyst based on the above understanding to achieve ∼80% C₂₊ FE at a high current density of 1.25 A cm⁻².