Electro-initiated co-precipitation for synthesis of copper-based powder catalysts

Abstract

Copper-based catalysts are extensively utilized in heterogeneous catalysis due to their cost-effectiveness and superior activity. However, their industrial production predominantly relies on conventional precipitation or impregnation methods, which inevitably generate substantial liquid and gaseous waste. Furthermore, these routes typically depend on nitrate precursors, where the production involves dissolving metals in strong acids, creating significant upstream environmental burdens. To address these issues, this work presents a facile and environmentally friendly electrochemical synthesis strategy. In this approach, a Cu mesh acts as the in-situ Cu²⁺ source, while OH^– generated from the hydrogen evolution reaction serves as the precipitating agent. Furthermore, by adding sodium citrate to the electrolyte, we can control the morphology of the catalyst, and by replacing the metal cations in the nitrate electrolyte, we can control the composition of the catalyst. Notably, a copper-cerium mixed oxide synthesized with 0.1 M cerium nitrate and 0.01 M sodium citrate delivers exceptional performance in CO oxidation, achieving a T₆₀ of 78 ℃ and a T₉₀ of 92 ℃. This enhanced activity is attributed to a unique dispersed nanosheet morphology that promotes the formation of Cu-Ce solid solutions and oxygen vacancies. Consequently, this green synthesis protocol holds great promise for sustainable industrial catalyst manufacturing.