Selective hydrogenation of phenol is a green strategy to produce cyclohexanone. Achieving high phenol conversion and cyclohexanone selectivity under mild conditions is a significant challenge in the design and synthesis of highly efficient catalysts. Herein, a highly efficient Pd@CN-rGO catalyst is synthesized by supporting Pd nanoparticles on the composite of ZIF-derived N-doped carbon and reduced GO (CN-rGO), which is prepared via annealing the composite of layered ZIF-L-Co and GO. The as-fabricated Pd1.2@CN-rGO-15 catalyst shows superior catalytic performance in phenol hydrogenation, and its turnover frequency (TOF) is 33.7 h–1, 3.2 times higher than that of Pd1.6/rGO and 1.5 times higher than that of Pd0.9@CN-rGO-0. The synergistic effect of CN and rGO leads to the uniform dispersion of Pd, high phenol adsorption ability, and strong antioxidizability of Pd, which contributes to the superior catalytic performance. More importantly, Pd@CN-rGO has good reusability in phenol hydrogenation. These findings will offer new insights into the development of high-performance catalysts for the selective hydrogenation of phenol.
Dong-Shun Deng,Guo-Qiang Han,Xiao Zhu,Xuan Xu,Yu-Tong Gong,Yong Wang
Mesoporous N-doped carbon supported palladium catalyst Pd@CN 0.132 was able to efficiently catalyze unprotected indole to indoline under mild conditions. In the aqueous system, a selectivity of 100% and conversion of 96% was achieved under 313 K and atmospheric hydrogen gas.
Ma Yao,Shen Yajing,Liu Mingjie,Lin Yuemin,Bao Zongbi,Yang Qiwei,Ren Qilong,Zhang Zhiguo
Pioglitazone has been developed as an effective insulin-sensitizing agent for the treatment of type II diabetes mellitus. Selective hydrogenation of the benzylidenethiazolidinedione exocyclic alkene is a committed step in the industrial manufacturing of pioglitazone. However, the strong coordination between metallic sites of commercial hydrogenation catalysts and benzylidenethiazolidinedione might cause catalyst poisoning and lead to poor activity and selectivity. In this context, an effective and anti-poisoning catalyst with highly dispersed palladium nanoparticles supported on biomass-derived nitrogen-doped carbon with mesoporous structures has been established. A systematic investigation of the structure–activity relationship was performed with a series of Pd/CN x by regulating the ratio of precursors D-glucosamine hydrochloride (GAH) and melamine, and it demonstrated that large specific surface area, rich pore structure and strong Pd–N interaction were essential for the high catalytic performance. The optimal Pd/CN 1.2 catalyst exhibited nearly 100% conversion and 95.5% selectivity under optimized reaction conditions. Remarkably, compared with commercial Pd/C catalyst, Pd/CN 1.2 displayed almost twice the catalytic productivity and provided better poisoning resistance and leaching resistance. Moreover, its stability was also acceptable and good activity could be maintained after exposed in the air for 4 months. Graphical Abstract