title: Enhancing the Catalytic Activity of Zn-Containing Magnetic Oxides in a Methanol Synthesis: Identifying the Key Factors.
abstract: 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.
authors.affiliation: Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Baird
authors.affiliation: Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States.
authors.forename: Jasper W
authors.initials: JW
authors.lastname: Dittmar
authors.affiliation: Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States.
authors.forename: Yaroslav B
authors.initials: YB
authors.lastname: Losovyj
authors.affiliation: Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States.
authors.forename: David Gene
authors.initials: DG
authors.lastname: Morgan
authors.affiliation: Department of Biology, Indiana University , Bloomington, Indiana 47405, United States.
authors.forename: Barry D
authors.initials: BD
authors.lastname: Stein
authors.affiliation: Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States.
authors.forename: Maren
authors.initials: M
authors.lastname: Pink
authors.affiliation: A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences , 28 Vavilov Street, Moscow 119991 Russia.
authors.forename: Nina V
authors.initials: NV
authors.lastname: Kuchkina
authors.affiliation: A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences , 28 Vavilov Street, Moscow 119991 Russia.
authors.forename: Elena S
authors.initials: ES
authors.lastname: Serkova
authors.affiliation: A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences , 28 Vavilov Street, Moscow 119991 Russia.
authors.forename: Olga L
authors.initials: OL
authors.lastname: Lependina
authors.affiliation: Department of Biotechnology and Chemistry, Tver State Technical University , 22 A. Nikitina Street, Tver 170026, Russia.
authors.forename: Maxim E
authors.initials: ME
authors.lastname: Grigoriev
authors.affiliation: Department of Biotechnology and Chemistry, Tver State Technical University , 22 A. Nikitina Street, Tver 170026, Russia.
authors.forename: Alexander I
authors.initials: AI
authors.lastname: Sidorov
authors.affiliation: Department of Biotechnology and Chemistry, Tver State Technical University , 22 A. Nikitina Street, Tver 170026, Russia.
authors.forename: Mikhail G
authors.initials: MG
authors.lastname: Sulman
authors.affiliation: A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences , 28 Vavilov Street, Moscow 119991 Russia.
authors.forename: Zinaida B
authors.initials: ZB
authors.lastname: Shifrina
authors.affiliation: 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.
authors.forename: Lyudmila M
authors.identifier: http://orcid.org/0000-0002-0438-8132
authors.initials: LM
authors.lastname: Bronstein
keywords: doping; hyperbranched; magnetic; methanol synthesis; nanoparticle; polymer; zinc