A team of researchers from the ITACA Institute at the Universitat Politècnica de València (UPV) and the Institute of Chemical Technology, a joint center of the Spanish National Research Council (CSIC) and the UPV, has discovered a new method for manufacturing metal nanocatalysts that is more sustainable and economical, with great potential in the industrial sector and whose use would contribute to the decarbonization of the sector. The work has been published in the ACS Nano journal.
This new method is based on the process of exsolution activated by microwave radiation. Exsolution is a method of generating metallic nanoparticles on the surface of ceramic materials. «Under conditions of high temperatures and reducing atmospheres (usually hydrogen), metallic atoms from the material’s own structure migrate to its surface, forming there metallic nanoparticles anchored to the surface. This anchoring significantly increases the resistance and stability of these nanoparticles, which positively affects the efficiency of these catalysts,» explains Beatriz García Baños, a researcher in the Microwave Area of the ITACA Institute at the UPV.
In the work now published in ACS Nano, researchers from the UPV and the CSIC have demonstrated that, thanks to the use of microwave radiation, this process can be carried out at more moderate temperatures and without the need to use reducing atmospheres.
«In this way, active nickel nanocatalysts can be generated in a more energy-efficient exsolution process. These catalysts have proven to be active and stable for the reaction of CO production from CO₂, obtaining an industrially interesting product that contributes to the decarbonization of the sector,» highlights Alfonso Juan Carrillo Del Teso, researcher of the Energy Conversion and Storage Group at the ITQ.
The exsolution process demonstrated in nickel nanoparticles has been carried out at temperatures around 400°C and in exposure times of a few seconds, while the conventional exsolution procedure in these materials occurs at temperatures of 900°C, with times of about 10 hours. In addition, this technology allows the exsolution to be carried out without the use of hydrogen.
«For all these reasons, we improve the sustainability of the process. Moreover, by being able to obtain the catalysts using milder temperatures and shorter exposure times, we reduce the process costs, which is also influenced by not having to use hydrogen as a reducing gas,» adds Beatriz García Baños.
The method developed by the UPV and CSIC team is primarily intended for use in high-temperature catalytic processes for renewable energy storage and conversion. It could also be applied in biogas reforming reactions for the production of synthesis gas (a precursor to liquid fuels), CO2 hydrogenation reactions applicable to Power-to-X systems, functionalization of electrodes for fuel cells and/or high-temperature electrolyzers.
Microwave-Driven Exsolution of Ni Nanoparticles in A-Site Deficient Perovskites. Andrés López-García, Aitor Domínguez-Saldaña, Alfonso J. Carrillo, Laura Navarrete, Maria I. Valls, Beatriz García-Baños, Pedro J. Plaza-Gonzalez, José Manuel Catala-Civera, and José Manuel SerraACS Nano 2023 17 (23), 23955-23964. DOI: 10.1021/acsnano.3c08534
Source: UPV’s Communication Area