Thermal decomposition of manganese carbonyl in supercritical CO2 as a simple and effective approach to obtain manganese oxide aerogels

Abstract

A novel approach to synthesize metal oxide aerogels is presented. The monolith aerogel structure is formed using dimanganese decacarbonyl as a precursor at elevated temperatures directly in supercritical CO₂. Unlike previously described and developed sol–gel approaches, the proposed synthetic route requires only several hours without any necessity either to add any additional reaction-promoting liquid agents or to perform prolonged gel aging, solvent exchange, or supercritical drying steps. The morphology of the obtained aerogels was studied by means of scanning and transmission electron microscopy. Using low-temperature nitrogen adsorption technique, it was demonstrated, that achievable surface area of the aerogels could be tailored by varying the precursor concentration. Eventually, aerogels with a specific surface area of up to 170 m²/g were obtained.

Alternate abstract:

Highlights

The one-stage/one-pot synthesis of manganese oxide aerogels is possible in supercritical CO₂.

In the presence of admixed oxygen, manganese carbonyls are easily thermally decomposed.

Dimanganese decacarbonyl used as a precursor converts into monolith aerogel structure.

The proposed one-step synthesis procedure is technologically simple and beneficial.

The properties of the obtained porous materials may be tailored by synthesis conditions.