Calcination temperature-dependent surface structure and physicochemical properties of magnesium oxide

Abstract

Magnesium oxide (MgO), as an exceptionally important inorganic material, has been widely studied in view of its unique surface properties, but the correlation between its surface structure and physicochemical performance is still scarce. Here we report the evolution of the surface structure and physicochemical properties of trapezoid-like MgO microparticles with calcination temperature by transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), thermal gravimetric analysis (TGA) and X-ray diffraction (XRD) techniques. The results demonstrated that along with the surface change of MgO from a smooth appearance to the structure composed of nanoparticles, its corresponding crystal structure evolved from mesocrystal to polycrystal, then to pseudomorph, and finally to cubic single crystal with the increase of calcination temperature ranging from 400 C to 1000 C. It also illustrated that the electrochemical capability of MgO was highly dependent on its crystal structure, whereas its catalytic activity had a good correlation with its textural properties (e.g., surface area and porosity) although the reaction selectivity was related to the calcination temperature. This work highlights the vital role of calcination temperature in determining the surface structure and physicochemical properties of the inorganic material MgO, which in turn will tailor its overall performance in the final applications.

Characterization of the surface properties of MgO using paper spray mass spectrometry

“…As shown in Fig. (a), it can be seen that for the product resulting from the reaction between Mg 2 + and C 2 O 4 2 − , it exhibits a trapezoidal structure, in good agreement with the previous reports . When the reaction system was altered to Mg 2 + and CO 3 2 − , needle‐like particles were obtained at a reaction temperature of 50 °C.…”

Synthesis and Structural Profile Analysis of the MgO Nanoparticles Produced Through the Sol-Gel Method Followed by Annealing Process

“…The calculation result of micro strain is very low and the straight lines with R 2 =0.6772 of the annealed MgO at temperatures of 500 o C were almost horizontal, this suggesting that the nanoparticles product is a lack of strain 34 .…”

Synthesis of Fluidized CO2 Sorbents Based on Diamine Coordinated to Metal–Organic Frameworks by Direct Conversion of Metal Oxides Supported on Mesoporous Silica

“…In a first step, the insoluble metal oxide precursor was prepared by incipient wetness impregnation of Mg nitrate in aqueous solution on a commercially available fluidized mesoporous silica, followed by a calcination step under air at 500 °C to obtain nanocrystalline MgO . The resulting metal oxide nanocrystals are well‐dispersed along the mesoporous silica, because XRD analysis did not revealed any diffraction peak corresponding to MgO phase, which indicates that the crystalline MgO domains are in the range of a few nanometers, thus ruling out the presence of large MgO agglomerates (see Figures e and S6 in the Supporting Information).…”

“…In af irst step, the insoluble metal oxide precursor was prepared by incipient wetness impregnationo fM gn itrate in aqueous solution on ac ommercially available fluidized mesoporouss ilica, followed by ac alcination step under air at 500 8C to obtain nanocrystalline MgO. [19] The resultingm etal oxide nanocrystalsa re well-dispersed alongt he mesoporouss ilica, because XRD analysisdid not revealed any diffraction peak corresponding to MgO phase, which indicates that the crystalline MgO domainsa re in the range of af ew nanometers, thus ruling out the presence of large MgO agglomerates (see Figures 1e and S6 in the Supporting Information). In addition, the occupancy of the mesoporousc avities of silica by the MgO phase was clearly revealed by the N 2 sorptioni sotherms and the pore-distribution plot, as shown in Figure 1c.S econdly,t he conversion of MgO/SiO 2 into MOF/SiO 2 was carriedo ut by soakingt his materiali naD MF solution containingt he MOF ligand.T oo btain the highest MOF loading while preventing the MOF phase to be detached from the surfaceo ft he mesoporouss ilica (as found for 21.0 wt %), the optimal MgO loading on SiO 2 was found to be 15.2 wt %, because muchl ower surface area was measured for 8.1 wt %.…”