Catalytic dehydrogenation of natural terpenes via CuPd alloy nanoparticles generated on mesoporous graphitic carbon nitride

Abstract

A facile wet‐chemical protocol for the synthesis of bimetallic CuPd alloy nanoparticles (NPs) anchored on mesoporous graphitic carbon nitride (m‐gCN), serving as both stabilizer and support material, was presented herein. The presented protocol allowed to synthesize nearly monodisperse CuPd alloy NPs with an average particle size of 3.9 ± 0.9 nm without use of any additional surfactants and to prepare CuPd/m‐gCN nanocatalysts with different Cu/Pd compositions (Cu 25 Pd 75 /m‐gCN, Cu 35 Pd 65 /m‐gCN, Cu 16 Pd 74 /m‐gCN, Cu 32 Pd 68 /m‐gCN, Cu 10 Pd 90 /m‐gCN, and Cu 50 Pd 50 /m‐gCN). After the detailed characterization of CuPd/m‐gCN nanocatalysts, they were utilized as catalysts in the dehydrogenation of terpenes. Among all tested nanocatalysts, Cu 50 Pd 50 /m‐gCN showed the highest activity in terms of the product yields within the same reaction time. Various parameters influencing the catalytic activity of Cu 50 Pd 50 /m‐gCN were studied using himachalene as a model substrate and the optimum conditions were determined. Under the optimized reaction conditions, the catalytic application of Cu 50 Pd 50 /m‐gCN nanocatalysts was extended to nine different terpenes and the corresponding products were obtained in high conversion yields (>90%) under mild conditions. A reusability test showed that Cu 50 Pd 50 /m‐gCN nanocatalysts can be re‐used up to four cycles without significant loss in their initial activity.