| Autor: |
Baird N; Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States., Dittmar JW; Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States., Losovyj YB; Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States., Morgan DG; Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States., Stein BD; Department of Biology, Indiana University , Bloomington, Indiana 47405, United States., Pink M; Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States., Kuchkina NV; A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences , 28 Vavilov Street, Moscow 119991 Russia., Serkova ES; A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences , 28 Vavilov Street, Moscow 119991 Russia., Lependina OL; A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences , 28 Vavilov Street, Moscow 119991 Russia., Grigoriev ME; Department of Biotechnology and Chemistry, Tver State Technical University , 22 A. Nikitina Street, Tver 170026, Russia., Sidorov AI; Department of Biotechnology and Chemistry, Tver State Technical University , 22 A. Nikitina Street, Tver 170026, Russia., Sulman MG; Department of Biotechnology and Chemistry, Tver State Technical University , 22 A. Nikitina Street, Tver 170026, Russia., Shifrina ZB; A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences , 28 Vavilov Street, Moscow 119991 Russia., Bronstein LM; Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States.; A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences , 28 Vavilov Street, Moscow 119991 Russia.; Faculty of Science, Department of Physics, King Abdulaziz University , Jeddah, Saudi Arabia. |
| Abstrakt: |
A new family of Ni-, Co-, and Cr-doped Zn-containing magnetic oxide nanoparticles (NPs) stabilized by polyphenylquinoxaline (PPQ) and hyperbranched pyridylphenylene polymer (PPP) has been developed. These NPs have been synthesized by thermal decomposition of Zn and doping metal acetylacetonates in the reaction solution of preformed magnetite NPs, resulting in single-crystal NPs with spinel structure. For the PPQ-capped NPs, it was demonstrated that all three types of metal species (Fe, Zn, and a doping metal) reside within the same NPs, the surface of which is enriched with Zn and a doping metal, while the deeper layers are enriched with Fe. The Cr-doped NPs at the high Cr loading are an exception due to favored deposition of Cr on magnetite located in the NP depth. The PPP-capped NPs exhibit similar morphology and crystallinity; however, the detailed study of the NP composition was barred due to the high PPP amount retained on the NP surface. The catalyst testing in syngas conversion to methanol demonstrated outstanding catalytic properties of doped Zn-containing magnetic oxides, whose activities are dependent on the doping metal content and on the stabilizing polymer. The PPP stabilization allows for better access to the catalytic species due to the open and rigid polymer architecture and most likely optimized distribution of doping species. Repeat experiments carried out after magnetic separation of catalysts from the reaction mixture showed excellent catalyst stability even after five consecutive catalytic runs. |
