Construction of Palladium Nanoparticles Modified Covalent Triazine Frameworks towards Highly-Efficient Dehydrogenation of Dipentene for p-Cymene Production

The generation of p-cymene from the catalytic dehydrogenation of dipentene is one of the most vital approaches for the synthesis of p-cymene in the chemical industry. Herein, CTF polymer was synthesized by an ionothermal method via using terephthalonitrile as monomer and NaCl-KCl-ZnCl2 ternary mixture as catalyst and solvent, and Pd/CTF catalyst was prepared by loading CTF matrix with Pd nanoparticles via a chemical reduction method. The as-obtained Pd/CTF catalyst with the loading amount of 5 wt% Pd showed remarkable catalytic activity in the dehydrogenation of dipentene to p-cymene with a high conversion rate of 100% and a high selectivity of 96% at the reaction temperature of 220 °C in a stainless-steel autoclave containing 0.1 MPa of Ar gas, and also exhibited good stability in the recycling tests. The strong interaction between Pd nanoparticles and CTF and the enhanced electron transfer at the metal-semiconductor interface contribute to the outstanding catalytic performance of Pd/CTF for the dehydrogenation of dipentene to p-cymene. This work demonstrates that the metal-semiconductor catalysts possessed excellent potential in the production of high-value-added chemical products from terpenes conversion.