Porous monodisperse manganese oxide nanospheres have been synthesized through an aqueous redox reaction between butanol and permanganate in the presence of dilute butyric acid. The as-synthesized materials have an approximate MnO2 stoichiometry, a surface area of 243 m2/g, and an average diameter of 379 nm ± 4.1%. Size tuning has been achieved by changing the concentration of permanganate used in the reaction. Sphere diameters range from 250 to 1000 nm, all with a relative standard deviation below 7%.
Hollow manganese oxides spheres have previously been prepared in a facile one-pot aqueous reaction between Mn2+ and permanganate in the presence of butyric acid. This thesis reports the synthesis of monodisperse manganese oxide spheres by substituting butanol for Mn2+.
We hypothesize that butyric acid emulsions, observed through the Tyndall effect, act as templates in the formation of spheres. Spheres are formed through the aggregation of individual platelets ranging from 5-10 nm in length. We also hypothesize the platelets are layered but lack higher order structure, resulting in amorphous materials.
All materials synthesized have been catalytically active in the conversation of isopropanol to acetone. Conversion ranged between 70‐95% at 200° C for all sphere sizes. Spheres with diameters less than 400 nm have a slightly higher conversation rate, although more trials are needed to statistically confirm this observation.
Richter, Ian, "Synthesis of Porous Monodisperse Manganese Oxide Nanospheres" (2014). Chemistry Honors Papers. 14.
The views expressed in this paper are solely those of the author.