Ultrafine Palladium Nanoparticles Immobilized On N-doped Porous Carbon Materials As A Highly Efficient Hydrogenation Catalyst

The performance of the supported ultrafine Pd nanocatalyst is affected by the size of the nanoparticles,the microscopic morphology,the support and the strong metal-support interaction.The researches show that the stabilization of ultrasmall Pd nanoparticles?NPs?on a suitable support is a common method to regulate the performance of catalysts.The ideal support can not only improve the dispersion of Pd NPs and narrow the particle size distribution,but also reduce the consumption of Pd and economic cost,enhance the strong metal support interaction,and thus improve the reusability of catalyst,reduce metal loss and aggregation.Among many support materials,nitrogen-doped porous carbon materials are widely known because the introduction of electron-rich nitrogen can firmly anchor Pd NPs and inhibit the agglomeration of Pd NPs.In this paper,according to different precursors,different nitrogen-doped porous carbon materials were designed to support ultrafine Pd nanocatalysts,and used in different catalytic hydrogenation reactions.The main research contents are as follows:?1?Based on the demand of green sustainable development,we use cheap biomass waste as raw material to obtain high specific surface area nitrogen-doped porous carbon material PNCM through simple high temperature carbonization,and as the support of Pd NPs.Because in-situ doped nitrogen atoms or groups interact with Pd NPs,compared with commercial Pd/C,the obtained Pd/PNCM catalyst has highly catalytic activity for phenol hydrogenation under green and mild conditions.?2?In heterogeneous catalytic reactions,the morphology of the support is critical to the stability and activity of the catalyst,so we designed nitrogen-doped hollow porous carbon nanospheres?HCNs?and used to stable ultrafine Pd NPs.The experimental results show that the resulting Pd/HCNs catalysts exhibit excellent activity and durability in the selective oxidation of 5-hydroxymethylfurfural?HMF?and hydrogenation of nitroarenes.?3?In order to further expand the type of catalyst support and design nanocluster type catalysts,the Pd-nanocluster-doped core–shell UiO-66-NH₂@COP nanoreactor?UiO-66-NH₂@COP@Pd?was designed using size-selective UiO-66-NH₂ and chemically stable COP as the supports,and Pd nanoclusters as the active sites.Due to the synergism among the three components of core UiO-66-NH₂,shell COP and active center Pd nanoclusters,the catalyst shows amazing reaction effect in hydrogenation of nitroarenes and reduction of 4-nitrophenol under mild reaction conditions.The research results in this paper are expected to provide some experimental basis for controlling the maximum utilization of Pd atom,building the heteroatom doped porous carbon material loaded ultrafine Pd NPs catalyst and its practical application in catalytic hydrogenation.