Magnesia Synthesis via Sol−Gel:  Structure and Reactivity

Abstract

2-Propanol decomposition at 200 °C on magnesium oxide prepared by the hydrolysis of magnesium ethoxide (sol−gel method) is reported. With hydrochloride acid, acetic acid, or ammonia as hydrolysis alkoxide catalysts, the acidity and the selectivity to propene of the catalysts follow the sequence, MgO (HCl) > MgO (acetic acid) > MgO (ammonia). In contrast, the basicity of the samples, defined as the ratio dehydrogenation rate/dehydration rate, is found to be depending on the particle size of the catalysts. The basicity trend found is MgO (acetic acid) > MgO (ammonia) > MgO (HCl) and it correlates well with the particle size determined by the Rietveld refinement.

Sol–Gel‐Derived, Calcium‐Based, Copper‐Functionalised CO2 Sorbents for an Integrated Chemical Looping Combustion–Calcium Looping CO2 Capture Process

“…The surface area, pore volume and pore radius of the calcined materials were determined by N 2 adsorption measurements and are summarised in Table 1. It has been reported that pure alumina xerogels (calcination at 800 °C) can have surface areas close to 300 m 2 g −1 ,24 whereas magnesium aluminium spinels and magnesium oxide (synthesised by a sol–gel technique and calcined at 500 °C) typically possessed lower surface areas of approximately 20025 and 10 m 2 g −1 ,26 respectively. A general observation from Table 1 is that the highest surface areas and largest pore radii were found in alumina‐based samples, with CuCa‐Al‐3.3:1‐acac possessing the highest surface area and pore radius of 47.6 m 2 g −1 and 3.4 nm, respectively.…”

MgO nanoparticles as antibacterial agent: preparation and activity

“…The use of magnesium alkoxides such as magnesium methoxide and magnesium ethoxide has been discussed in a few reports (Bokhimi, 1995;Portillo et al, 1996;Jung et al, 2003 a, b;Stengl et al, 2003). Many factors such as temperature, time, pH, catalytic agent for gel formation, and the environmental conditions can significantly affect the characteristics of the nanoparticles (Klabunde et al, 1996;Bokhimi et al, 1995).…”

Impact of surfactants and acids on the sol–gel synthesis of MgO aerogels

“…As a consequence, large research efforts are devoted to the synthesis of MgO with high specific surface areas to enhance its effectiveness in adsorption processes or as a solid base catalyst [1,[8][9]. In conventional approaches, MgO is synthesized by heating brucite, Mg(OH) 2 , or by thermal decomposition of various magnesium salts at high temperatures to yield periclase, MgO [10][11][12][13][14]. In both methods the obtained particles are non-uniform in shape with relatively large sizes.…”