Preparation of iron molybdate catalysts for methanol to formaldehyde oxidation based on ammonium molybdoferrate(II) precursor



Nikolenko, NV, Kozhevnikov, IV ORCID: 0000-0003-2453-5256, Kostyniuk, AO, Bayahia, H and Kalashnykov, Yu V
(2018) Preparation of iron molybdate catalysts for methanol to formaldehyde oxidation based on ammonium molybdoferrate(II) precursor. JOURNAL OF SAUDI CHEMICAL SOCIETY, 22 (3). pp. 372-379.

Access the full-text of this item by clicking on the Open Access link.

Abstract

It was demonstrated that iron molybdate catalysts for methanol oxidation can be prepared using Fe(II) as a precursor instead of Fe(III). This would allow for reduction of acidity of preparation solutions as well as elimination of Fe(III) oxide impurities which are detrimental for the process selectivity. The system containing Fe(II) and Mo(VI) species in aqueous solution was investigated using UV–Vis spectroscopy. It was demonstrated that three types of chemical reactions occur in the Fe(II)–Mo(VI) system: (i) formation of complexes between Fe(II) and molybdate(VI) ions, (ii) inner sphere oxidation of coordinated Fe(II) by Mo(VI) and (iii) decomposition of the Fe–Mo complexes to form scarcely soluble Fe(III) molybdate, Mo(VI) hydrous trioxide and molybdenum blue. Solid molybdoferrate(II) prepared by interaction of Fe(II) and Mo(VI) in solution was characterized by EDXA, TGA, DTA and XRD and a scheme of its thermal evolution proposed. The iron molybdate catalyst prepared from Fe(II) precursor was tested in methanol-to-formaldehyde oxidation in a continuous flow fixed-bed reactor to show similar activity and selectivity to the conventional catalyst prepared with the use of Fe(III).

Item Type: Article
Uncontrolled Keywords: Iron molybdate catalyst, Ammonium molybdoferrate (II), Methanol oxidation, Formaldehyde
Depositing User: Symplectic Admin
Date Deposited: 26 Oct 2016 11:00
Last Modified: 19 Jan 2023 07:27
DOI: 10.1016/j.jscs.2016.04.002
Open Access URL: http://dx.doi.org/10.1016/j.jscs.2016.04.002
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3004019