Recently, our center in collaboration with Prof. Botao Qiao, successfully prepared sinter-resistant Au nanocatalysts by rapidly constructing strong metal-support interactions (SMSI) via microwave-assisted treatment. Compared to conventional high-temperature reduction methods for SMSI formation, our microwave-assisted strategy is more efficient and energy-saving, offering new insights for the design of sinter-resistant noble-metal catalysts and a deeper understanding of SMSI effects.
Supported metal catalysts are extensively employed in modern chemical processes, however, they prone to sintering and deactivating during long-term operation at elevated temperatures. Catalyst deactivation often results in profit losses because the regeneration of supported metal catalysts typically involves leaching, purification, and reloading processes, which are tedious and complicated. The SMSI has garnered significant attention due to its dual benefits: stabilizing metal particles and modulating the catalytic activity and selectivity by altering the geometric and electronic structure of the active metal sites. Conventional SMSI formation relies on high-temperature reduction, yet such treatments inevitably cause metal sintering before the overlayer can form. Consequently, developing new methods to rapidly construct SMSI under milder conditions, avoiding the traditional high-temperature hydrogen reduction, is critical for the design of highly efficient catalysts.
Microwave irradiation has been widely utilized as a cost-effective heating method for several decades owing to its rapid, energy efficient, and efficient heating capability. Conventional heating approaches rely on a slow thermal radiation process that results in extended reaction times (ranging from several hours to days), poor controllability, and significant energy consumption. In this work, a novel, ultrafast, and highly efficient microwave induced approach was developed: to construct SMSI in the Au/CeO2 system through microwave treatment in the presence of L-ascorbic acid. This method of constructing SMSI is more facile and energy-saving, compared to the traditional high-temperature reduction process, and the energy consumption of reduction-induced SMSI is about 30 times that of the former. Moreover, the degree of encapsulation can be tuned by adjusting the duration of the microwave treatment, with overlayer thickness increasing as processing time is extended. Due to the overlayer of Au NPs, the Au/CeO2-MW5 catalysts with SMSI exhibited enhanced stability during 100 h of continuous reaction. In addition, this methodology can be extended to other catalyst systems, such as Au/TiO2 and Au/ZrO2, showing its universality in the synthesis of sintering-resistant supported metal catalysts. This work provides a novel yet straightforward method for developing metal nanocatalysts with enhanced stability and contributes to a deeper understanding of the SMSI effect.
The related research results entitled “Microwave-assisted rapid construction of strong metal-support interactions for sinter-resistant gold nanocatalysts” has been published in Applied Catalysis A, General. The first author is Yunxia Liu, a doctoral student in our center. This research is supported by the National Natural Science Foundation of China and the International Partnership Program of the Chinese Academy of Sciences.
Relevant link: https://doi.org/10.1016/j.apcata.2025.120252
