Flow and Batch Minute-Made Synthesis of Ce-UVM‑7 Using Microwave-Assisted Reaction: Scaling-Up, Optical and Catalytic Applications, and Impact Assessment

• Published in: ACS sustainable chemistry & engineering Vol. 12; no. 35; pp. 13208 - 13219
• Main Authors: Rodríguez-Carrillo, Cristina, Benítez, Miriam, De los Reyes, Ruth, El Haskouri, Jamal, Amorós, Pedro, Ros-Lis, Jose V.
• Format: Journal Article
• Language: English
• Published: American Chemical Society 02-09-2024
• Subjects: microwave-assisted synthesis; mesoporous silica; sunscreen; cerium; scale-up; LCA; flow synthesis
• ISSN: 2168-0485; 2168-0485
• DOI: 10.1021/acssuschemeng.4c03974

This study introduces the first synthesis of a cerium-containing UVM-7 material, a bimodal mesoporous silica material. It was prepared swiftly using microwave-assisted synthesis powered by solid-state generators in combination with the atrane route. This synthesis process has been meticulously optimized and scaled-up in batch form. We also developed a flow synthesis procedure for Ce-UVM-7. These materials exhibit homogeneous Ce distribution within the UVM-7 silica structure with a Si/Ce ratio of up to 15. The scaled-up synthesis process allows the preparation of 35 g of Ce-UVM-7 in just 10 min of irradiation, with batch and flow synthesis methods achieving a yield of 11 g h–1. We studied the optical properties, sun protection factor (SPF), and ROS scavenging properties of the resulting materials. The results show that the band gap decreases as the cerium concentration increases, reaching only 3.15 eV for the most concentrated sample and a high SPF. The peroxidase activity of materials prepared with a Si/Ce ratio of 25 is higher than that found for pure CeOx. Life cycle assessment confirms a significant reduction in the environmental impact during the scale-up process, with values of approximately 8 points in the single score for the preparation of 1 kg of Ce-UVM-7, further highlighting the efficiency and sustainability of this novel synthesis method.