APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Lu Lin,Haiou Liu,Xiongfu Zhang
Rational design of efficient approaches to fabricate MOFs-coated core-shell composites is promising but challenging. We report here the encapsulation of Pd nanoparticles (Pd NPs) supported flower-like ZnO (F-ZnO) microspheres with ZIF-8 shell through a facile strategy, in which the formation and immobilization of Pd NPs on F-ZnO supports and the subsequent growth of ZIF-8 shells over them are effectively integrated into one-pot synthetic route. Importantly, the utilization of ZnO both as support of Pd NPs and Zn 2+ source of ZIF-8 is favorable for the implement of one-pot synthesis, due to its functions in anchoring Pd NPs and inducing ZIF-8 formation. Further insights into the morphological influence of zinc oxide particles on the resulting materials indicate that the flower-like microspheres with 2D nanosheets as subunits also benefit the coating of Pd NPs supported cores with ZIF-8, resulting in a well-defined core-shell catalyst. The achieved catalyst deliveries remarkable performance in terms of selectivity, anti-poisoning and recyclability in the liquid hydrogenations of alkenes.
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2014
·
IF 2.235
Qingshan Zhao,Chan Bai,Wenfeng Zhang,Yang Li,Guoliang Zhang,Fengbao Zhang,Xiaobin Fan
Immobilization of metal complexes on solid supports is an efficient approach to remedy the drawbacks of homogeneous catalysis. In this study, an in situ strategy of synthesis and immobilization of a copper (salen) complex onto graphene oxide (GO) support has been developed. To provide the salen ligands, GO was covalently modified with an aminosilane, followed by condensation with salicylaldehyde. The copper (salen) complex was subsequently synthesized and simultaneously immobilized onto the GO surface with a designed tetrahedral chelate structure. The immobilized copper (salen) complex [Cu(salen)–f–GO] kept the two-dimensional sheetlike character of GO and was demonstrated to be highly effective for the epoxidation of olefins. It could be readily reused for successive twelve times without discernible activity and selectivity deterioration, which displays potential for practical applications.
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2014
·
IF 2.235
Lu Lin,Tong Zhang,Xiongfu Zhang,Haiou Liu,King Lun Yeung,Jieshan Qiu
In this work, we fabricated a new type of Pd/SiO2@ZIF-8 core–shell catalyst composed of a Pd/SiO2 microsphere as the core and a ZIF-8 membrane as the shell. The preparation procedure involves first loading Pd nanoparticles onto nonporous SiO2 microspheres to obtain the Pd/SiO2 core and then coating a perfect layer of ZIF-8 shell on the core by electrostatic induction to form a Pd/SiO2@ZIF-8 core–shell structure. It is crucial that the modification of the Pd/SiO2 core with polyelectrolyte was employed to improve the charge distribution of the core surface and preferably adsorb Zn2+ cations in the synthesis solution so as to assist the formation of a continuous ZIF-8 shell. The compactness and thickness of the shell were optimized by increasing the number of cycles of ZIF-8 growth. The hydrogenations of alkenes with different molecular sizes showed that the Pd/SiO2@ZIF-8 catalysts can provide excellent product selectivity and antipoisoning and antileaching properties for the hydrogenations of alkenes.
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2017
·
IF 3.615
Fu Yang,BangBang Wang,Shijian Zhou,Saifu Long,Xianfeng Liu,Yan Kong
Micropore can efficiently tailor the diffused rate of reactant molecule in heterogeneous catalysis and enhance collision frequency with catalytic active sites, hence increasing catalytic properties. In this study, boosting catalytic activity for olefins epoxidation was obtained using micropore-enriched CuO-based silica catalyst. This special catalyst incorporated with highly-dispersed copper oxides was directly fabricated with anionic surfactant chelating Cu 2+ as the template. Dispersed CuO species were in situ produced and encapsulated in the channels of mesoporous silica , avoiding the repeated calcination in the conventional modification process. Meanwhile, massive micropores (ca. 1.6 nm) were directly formed. In addition, to receive optimal catalytic performance, controllable amounts of Cu 2+ were employed for modifying anionic micelles . This obtained catalyst exhibited obviously stronger reducibility and better dispersity of CuO in comparison with the post-impregnated sample, more interestingly, the introduction of Cu 2+ in the assemble process improved structural properties of silica. In addition, a proper loading (Cu/Si = 4.34%) of CuO was found to be preferable in the catalytic process. Finally, catalytic results revealed that the micropore-enriched catalyst exhibited obviously higher catalytic activity as compared to the mesoporous catalyst, and its further applications in various olefins epoxidation were preferable.
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2025
·
IF 13.1
Shihao Su,Guojun Lv,Jialing Shen,Fuxin Wang,Lachgar Oussama,Yan Chen,Shengnan Xu
In the tandem synthesis of 1,2-cyclohexanediol, solvents such as acetonitrile are often added to eliminate the immiscibility of cyclohexene with water and accordingly strengthen the interphase mass transfer; however, the usage of solvents artificially increases the solvent separation procedure, enhancing the energy consumption and decreasing the economic benefits of the reaction process. Hence, the development of the solvent-free Pickering interfacial tandem catalysis of cyclohexene to 1,2-cyclohexanediol is extremely appealing. In this study, β-MnO2 and Mn2O3 were prepared by calcining γ-MnO2 synthesized with the hydrothermal synthesis method and concurrently served as a colloidal emulsifier and a heterogeneous catalyst in the Pickering interfacial tandem catalysis of cyclohexene to 1,2-cyclohexanediol at room temperature in the presence of the oxidant molecular oxygen and the co-oxidant isobutyraldehyde. The prepared β450-MnO2 sample revealed the best tandem catalysis performance, achieving a cyclohexene conversion of 99.4% and a 1,2-cyclohexanediol selectivity of 83.6% within 4 h of reaction, which can be ascribed to the highest Mn4+/Mn3+ ratio and the greatest concentration of oxygen vacancies as well as the most stable Pickering emulsion. At the same time, density functional theory (DFT) studies further confirmed that isobutyraldehyde and molecular oxygen could be more easily adsorbed and activated by β450-MnO2 in comparison with the other catalyst samples, benefiting its eminent catalytic epoxidation performance. In addition, a possible reaction mechanism for the β450-MnO2 catalyst catalyzing cyclohexene into 1,2-cyclohexanediol in the Pickering interfacial tandem catalytic reaction system was put forward and validated through quenching experiments as well as in situ infrared characterization. The synthesized β450-MnO2 catalyst exhibited reusability for greater than 5 cycles, and meanwhile, the Pickering interfacial tandem catalytic reaction system can be expanded to a spread of linear and cyclic alkene substrates, highlighting the superiority of the β450-MnO2 catalyst. These findings verify that the synthesized β450-MnO2 catalyst is capable of being utilized as an efficient and stable catalyst for the Pickering interfacial catalytic conversion of alkenes into 1,2-diols at room temperature.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）