High-Performance Pd/AC Catalyst for Meropenem Synthesis Based on Selective Surface Modification of Activated Carbon

Activated carbon (AC) was treated with nitric acid, hydrogen peroxide, and urea. The obtained products were then used as supports for the preparation of palladium/activated carbon (Pd/AC) catalysts. The characterization results revealed that the AC textural structure and surface properties were selectively modified via different treatments, and the surface functional groups of the supports could affect the particle size, dispersion, and chemical states of the Pd nanoparticles. The surface of the urea-treated AC (AC-U) contained more carbonylic groups and nitrogenous species but fewer hydroxylic and carboxylic groups than the surfaces of the ACs subjected to other treatments. Consequently, in the hydrogenation synthesis of meropenem, the Pd/AC-U catalyst provided a higher meropenem yield and lower amounts of impurities in the meropenem product than the other catalysts. The nitrogenous groups not only provided efficient anchoring sites for Pd nanoparticles, improving the reaction activity, but also reduced the side reactions, decreasing the impurity content in the product.

Automated summary

The textural structure and surface properties of activated carbon were selectively modified through different treatments, with urea-treated AC containing more carbonylic groups and nitrogenous species. The Pd/AC-U catalyst showed higher meropenem yield and lower impurity content in the product due to the efficient anchoring sites for Pd nanoparticles provided by the nitrogenous groups and decreased side reactions.