Iron(III) Oxide Nanoparticles as Catalysts for the Formation of Linear Glycine Peptides

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• 作者：Thomas Georgelin ; Mariame Akouche ; Maguy Jaber ; Yuriy Sakhno ; Lucrece Matheron ; Frederic Fournier ; Christophe Mé ; thivier ; Gianmario Martra and Jean-Francois Lambert
• 刊名：European Journal of Inorganic Chemistry
• 出版年：2017
• 出版时间：January 3, 2017
• 年：2017
• 卷：2017
• 期：1
• 页码：198-211
• 全文大小：2711K
• ISSN：1099-0682c

文摘

We have studied the behavior upon thermal activation of glycine adsorbed on three well-characterized Fe³⁺ oxide nanoparticle phases, maghemite, hematite, and akaganeite. The behavior of the adsorbed molecules and of the nanoparticle surfaces was monitored by four main experimental techniques, thermogravimetric analysis/differential thermal analysis (TGA/DTA), XPS, infrared spectroscopy (IR), and mass spectrometry. Glycine polymerizes by peptide bond formation in the 180–190 °C temperature range, which is somewhat higher than on previously studied oxides such as silica or alumina, giving mostly short linear peptides. At slightly higher temperatures, under an inert gas, the iron oxyhydroxides act as stoichiometric oxidants and cause oxidative degradation of the peptides formed in the previous step while they are reduced to FeO; under air, dioxygen causes reoxidation of the nanoparticle surfaces so that the overall effect is a catalytic oxidation by O₂. While the direct formation of linear peptides may be beneficial to the growth of prebiotic complexity, the redox reactivity of the supports limits the temperature stability range of the oligopeptides.