Hongwei Li,Zhibin Liu,Pengju Lei,Jichong Xia,Shoudeng Wang,Guixian Li,Xinhong Zhao,Dong ji
A PEG-400-assisted impregnation-precipitation method synthesized 50 wt% Ni/AC catalysts for dinitrotoluene (DNT) hydrogenation. Optimal PEG-400 dosage (0.4 g) suppressed Ni agglomeration via steric hindrance, yielding uniform 10.9-nm Ni nanoparticles and mesopores (12.24 nm). This enhanced dispersion and mass transfer, achieving complete DNT conversion in 5 min under mild conditions (120 °C, 2.1 MPa H 2 ) with 99.99% TDA selectivity and zero tar. The catalyst retained > 95.5% conversion and > 97.3% selectivity over 10 cycles, demonstrating exceptional stability. PEG's dual role in structural control and pore engineering effectively addresses the dispersion challenges inherent to high-loading catalysts. Graphical PEG-400 directs the synthesis of a 50 wt% Ni/AC catalyst via impregnation-precipitation. Optimal PEG dosage (0.4 g) enables steric hindrance control, yielding uniform 10.9-nm Ni nanoparticles and mesopores. This catalyst achieves complete DNT hydrogenation to TDA in 5 min (120 °C; 2.1 MPa H 2 ) with > 99.99% selectivity and zero tar, retaining high performance over 10 cycles.
PtRh bimetallic nanoparticle (NP)-encaged hollow mesoporous silica nanoreactors (PtRh@HMSNs) are prepared by employing metal-ion-containing charge-driven polymer micelles as templates. These nanoreactors feature ∼1–2 nm PtRh NPs in ∼11 nm hollow cavities of HMSNs. Among various PtxRhy@HMSNs, Pt0.77Rh1@HMSNs show the best catalytic performance for toluene hydrogenation. Under 30 °C, atmospheric H2 pressure, and a toluene/(Pt+Rh) molar ratio of 200/1, Pt0.77Rh1@HMSNs reach 100.0% of methyl cyclohexane yield and demonstrate a much better catalytic performance than monometallic Pt@HMSNs and Rh@HMSNs and their physical mixtures. Moreover, Pt0.77Rh1@HMSNs exhibit a good catalytic stability during recycling experiments. The enhanced performance of Pt0.77Rh1@HMSNs is ascribed to the interaction between Pt and Rh, the beneficial effect of the relatively large mesoporous channels for mass transfer, as well as the confinement effect of functional NPs inside hollow cavities.