Platinum clusters deposited on maghemite applied to preferential oxidation of CO under hydrogen rich conditions (PROX-CO)

Author(s)

Aragao, I. B. ^[1] ; Bueno, J. M. C. ^[2] ; Zanchet, D. ^[1]

Affiliation

^[1] Univ Estadual Campinas, UNICAMP, Inst Chem, CP 6154, BR-13083970 Campinas, SP - Brazil

^[2] Univ Fed Sao Carlos, UFSCar, Dept Chem Engn, Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: APPLIED CATALYSIS A-GENERAL; v. 568, p. 86-94, NOV 25 2018.
• Web of Science Citations: 2

Abstract

Pt-FeOx catalysts have been showing excellent performance on several catalytic reactions involving bifunctional mechanisms. Here, Chini's carbonyl oligomers were used as a precursor to obtain Pt nanoparticles (Pt-NP) anchored on maghemite, gamma-Fe2O3. The Pt-NP diameter were in the range of 1.5 nm and the catalysts were active in preferential oxidation of CO under H-2 rich atmosphere (PROX-CO reaction), without pretreatments. The catalytic behavior after the first heating ramp, under consecutive cycles, improved, almost triplicating the CO conversion at lower temperatures, around 353 K. A detailed characterization was performed and showed that the support, due the presence of Pt -NP, went through a phase transformation under reaction conditions, from gamma-Fe2O3 (Fe(III)) to Fe3O4 (Fe(II,III)), indicating that the presence of Fe(II) species are stabilized under PROX-CO and contribute to overall performance of the catalyst. As comparison, the bare Fe2O3 support as well as a catalyst prepared by depositing the same Chini's carbonyl oligomers on SiO2 support showed negligible activity at these low temperatures. (AU)

• FAPESP's process: 14/21988-7 - Carbonyl organometallic precursors for supported catalysts synthesis: in situ studies and hydrogen production
• Grantee: Isaias Barbosa Aragão
• Support Opportunities: Scholarships in Brazil - Doctorate