γ-Alumina Supported Copper Oxide Nanostructures Promoted with Ruthenium Oxide (RuO₂-CuO/Al₂O₃) and Palladium Oxide (PdO-CuO/Al₂O₃): Efficient Electrodes for Heterogeneous Catalysis of Ammonia Electrooxidation

Abstract

RuO2 and PdO promoted CuO/Al2O3 mixed metal oxide nanostructures synthesized via co-impregnation technique demonstrated a robust electrocatalytic activity towards ammonia electro-oxidation (AEO). Physio-chemically characterized RuO2-CuO/Al2O3 and PdO-CuO/Al2O3 catalyst powders exhibited high electrochemical active surface area (ECSA), the highest being shown by 1% RuO2-CuO/Al2O3. All fabricated electrodes displayed pleasing electroactive response towards AEO but ternary metal oxides showed superior and promoted catalytic output owing to their larger ECSA, higher current densities (j), larger diffusion coefficients (D°), greater apparent rate constants (kapp), and lower charge transfer resistance (Rct) values. Lower values of Rct obtained from EIS indicated the facilitation of electro-oxidation process over modified electrodes. The finest catalysis performance is expressed by 1% RuO2-CuO/Al2O3 producing the maximum oxidation current. All of the promoted CuO/Al2O3 mixed metal oxide exhibited excellent stability and reproducibility in analyte solution. Consequently, γ-Al2O3 supported metal oxide electrocatalysts can be of great socio-economic significance by enhancing the energy production kinetics thereby achieving a higher energy output.

Progress in the Preparation of Metal Oxide Electrodes for the Electrochemical Treatment of Organic Wastewater: A Short Review

“…Compared with the above types of electrodes, metal oxide electrodes have higher catalytic activity and electrochemical stability [62][63][64], which can improve the reaction rate of the electrode. They not only have a longer service life, but can also be applied in a wide range of pH values.…”

Cu/Fe embedded N-doped carbon as a highly durable oxygen reduction electrocatalyst

“…[1][2][3] Among the different renewable energy technologies, zinc-air batteries are promising due to higher power/energy density and zero emissions. [4][5][6][7][8][9] The oxygen reduction reaction (ORR) is a crucial reaction in zinc-air batteries that governs the overall performance. [10][11][12][13][14] However, the sluggish kinetics have limited the practical performance and durability of batteries.…”