Synthesis of manganese oxide octahedral molecular sieves containing cobalt, nickel, or magnesium, and the catalytic properties for hydration of acrylonitrile

Abstract

An octahedral molecular sieve known as OMS-1 has todorokite structure composed of magnesium and manganese oxides, which was named as Mg-todorokite here. Octahedral molecular sieves containing cobalt

Aging promotes todorokite formation from layered manganese oxide at near-surface conditions

“…Moreover, natural Mn oxides have long been recognized as playing an important role in controlling and influencing the release, transfer, availability and toxicity of many nutrient elements, heavy metals and organic contaminants in soils and sediments (Oscarson et al 1981;Stepniewska et al 2004). Many studies have showed that the environmental behaviors of Mn oxides depend on their structures (especially for substructure), morphologies, and chemical compositions (Villalobos et al 2005;Feng et al 2007;Onda et al 2007;Zhao et al 2009). Layered birnessites (or buserite) are common manganese oxides in soils and sediments, and their environmental behaviors will be influenced by changing of their substructures, compositions, and transformation to other manganese oxides with aging.…”

Transformation of Co-containing birnessite to todorokite: Effect of Co on the transformation and implications for Co mobility

“…As phyllomanganate precursors often have transition 112 metals sorbed at their surface and/or incorporated within their octahedral layers, the 113 fate of these elements during the phyllomanganate-to-tectomanganate conversion is of 114 special interest for their geochemical cycling (e.g., Siegel and Turner, 1983;Atkins et al, 2014Atkins et al, , 2016. Experimental investigations of the mobility and fate of metals during todorokite formation from layered precursors however, show mixed results, with studies reporting both the incorporation of metal ions into the framework of newly formed todorokite (Yin et al, 1994;Ching et al, 1999;Nicolas-Tolentino et al, 1999;Kumagai et al, 2005;Onda et al, 2007) or the loss of metal ions from precursor 120 birnessite with only the surface adsorption of metal ions onto newly formed 121 todorokite (Atkins et al, 2016).…”

Synthesis of todorokite-type manganese oxide from Cu-buserite by controlling the pH at atmospheric pressure

“…Todorokite-type manganese oxide (OMS-1) is one group in the OMS family, containing 3 Â 3 tunnel structure with a pore size of 6.9 Å [7]. The OMS-1 materials have been found to have a wide variety of applications as catalysts, absorbents, and battery materials due to their unique structures and physical and chemical properties [7][8][9][10]. Todorokite was firstly synthesized by Golden et al through autoclave treatment of Mg 2+ exchanged birnessite (Mg-buserite) under hydrothermal conditions [11].…”