Preparation Of Mesoporous Carbon Nitride-based Hydrogenation Catalyst And Its Application In Hydrogenation Of ?-pinene

The selective hydrogenation of ?-pinene is an important reaction in the utilization and deep processing of forest materials.At present,the catalyst for industrially catalyzing the selective hydrogenation of ?-pinene is generally Pd/C catalyst,which has disadvantages of high cost,low selectivity,leaching and agglomeration of active components.As a new inorganic non-metallic material,mesoporous graphite phase carbon nitride has the advantages of acid and alkali resistance,high temperature resistance and easy modification.Its unique electronic structure can produce ?-?interactive with ?-pinene molecule.Therefore,from the perspective of green chemistry,a series of graphite phase carbon nitride-based catalysts were prepared using graphite phase carbon nitride as a catalyst carrier.The catalysts of this series have high catalytic activity and selectivity,the products and catalysts were easy to separate,and the catalysts have good repeatability.The details are as follows:A palladium-supported mesoporous graphite phase carbon nitride catalyst was prepared and characterized in aqueous solution using palladium chloride as a palladium source.The prepared Pd/MCN was used to catalyze the selective hydrogenation of ?-pinene to cis-pinane.The catalyst exhibited good performance with94.15% conversion and 75.37% selectivity for cis-pinane under the optimal condition(140 ?,hydrogen pressure 4 MPa,150 min,catalyst usage 1.5 wt%).Compared with the Pd/C catalyst with the same Pd loading and the same reaction conditions,the reaction conversion and cis-pinane selectivity are increased by 14% and5%,respectively,and the catalyst could be repeat 6 times or more.The mesoporous graphite phase carbon nitride catalyst loaded with amorphousphase nickel-boron alloy was prepared and characterized by using nickel chloride as the nickel source and sodium borohydride as the boron source and reducing agent.The prepared NiB/MCN was used to catalyze the selective hydrogenation of ?-pinene.Under the optimal reaction conditions(140 ?,hydrogen pressure 4 MPa,150 min,catalyst usage 1.5 wt%),99.30% ?-piene conversion,and 99.9% cis-pinane selectivity were obtained,the catalyst can be reused more than 7 times.Nickel chloride was used as the nickel source,sodium tungstate was used as the tungsten source,sodium borohydride was used as the boron source and reducing agent.The mesoporous graphite phase carbon nitride catalyst loaded with nickel tungsten boron ternary alloy was prepared and characterized in aqueous solution.The prepared NiWB/MCN is used to catalyze the selective hydrogenation of ?-pinene to cis-pinane.Under the optimal reaction conditions(124 ?,hydrogen pressure 2 MPa,122 min,catalyst usage 1.5 wt%),99.30% ?-piene conversion,and 99.9% cis-pinane selectivity were obtained,and the reaction conditions are milder than NiB/MCN.The catalyst can be reused more than 7 times.In this paper,a mesoporous graphite phase carbon nitride-based metal catalyst was used to catalyze the selective hydrogenation of ?-pinene.The system has high conversion and high selectivity to cis-pinane,simple catalyst recovery and high reusability.It provides a new method for the deep processing and high value utilization of ?-pinene.It also provides a new idea for the application of mesoporous graphite phase carbon nitride in the field of hydrogenation reaction.