A new gold-perovskite catalyst achieves record-high acetaldehyde yields from bioethanol at lower temperatures.
Acetaldehyde plays an important role as a chemical building block and is commonly produced through the ethylene-based Wacker oxidation process. However, this traditional method is both expensive and environmentally damaging. Researchers have long sought a cleaner and more sustainable alternative, such as converting bioethanol into acetaldehyde through selective oxidation. Yet, most catalysts developed for this purpose face a difficult balance between activity and selectivity, often producing less than 90% acetaldehyde.
A major advance came over a decade ago when Liu and Hensen identified a unique Au0-Cu+ interaction in an advanced Au/MgCuCr2O4 catalyst. Their system delivered over 95% acetaldehyde yield at 250°C and maintained its performance for more than 500 hours. Although this was a major breakthrough, scientists continue to search for safer and more efficient catalysts that can drive ethanol oxidation effectively at lower temperatures.
A New Generation of Perovskite Catalysts
Recently, the research team led by Prof. Peng Liu (Huazhong University of Science and Technology) and Prof. Emiel J.M. Hensen (Eindhoven University of Technology) reported significant progress in selective ethanol oxidation. They developed a series of Au/LaMnCuO3 catalysts with varying Mn/Cu ratios, among which the Au/LaMn0.75Cu0.25O3 composition exhibited a pronounced synergistic effect between gold nanoparticles and moderately Cu-doped LaMnO3 perovskite. This synergy enabled efficient ethanol oxidation below 250oC, outperforming the previously benchmarked Au/MgCuCr2O4 catalyst. The findings were published in the Chinese Journal of Catalysis.
To improve the efficiency of converting bioethanol into acetaldehyde—a valuable chemical used in plastics and pharmaceuticals, researchers developed a new class of catalysts based on perovskite materials. These supports were synthesized using a sol-gel combustion method and then coated with gold nanoparticles. By adjusting the ratio of manganese to copper in the perovskite structure, the team identified an optimal composition (Au/LaMn0.75Cu0.25O3) that achieved a high acetaldehyde yield of 95% at 225°C and maintained stable performance for 80 hours.
Catalysts with higher copper content were less effective, largely because copper tends to lose its active form during the reaction. The improved performance of the optimized catalyst is linked to a cooperative interaction between gold, manganese, and copper ions.
Decoding the Catalyst’s Atomic-Level Mechanism
To better understand how these elements work together, the researchers used advanced computational techniques, including density functional theory and microkinetic simulations. These studies revealed that doping copper into the perovskite creates active sites near the gold particles that help activate oxygen and ethanol molecules more efficiently. The optimized catalyst also showed a lower energy barrier for key reaction steps, making the process more efficient. Both experimental and theoretical results highlight the importance of fine-tuning the catalyst composition to achieve better performance.
Reference: “Unveiling the Au-Mn-Cu synergy in Au/LaMnCuO3 catalysts for selective ethanol oxidation” by Jie Wang, Lulu Chen, Lijun Yue, Ivo A.W. Filot, Emiel J.M. Hensen and Peng Liu, 6 August 2025, Chinese Journal of Catalysis.
DOI: 10.1016/S1872-2067(25)64686-9
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