Authors:Ekkachai Kanchanatip, Nurak Grisdanurak, Raumporn Thongruang, and Arthit Neramittagapong
measured by thermogravimetricanalysis and differential thermal analysis (TGA–DTA), using Shimadzu TGA-50 and DTA-50. The crystalline phase was characterized by X-ray diffraction (XRD) using Cu K α radiation (λ = 0.15418 nm) on a Bruker AXS diffractometer
Authors:G. Lizia Thankam and Neelakantan Thurvas Renganathan
.1 Metakaolin in mid '90s Though few formulations were flourishing in the '80s on metakaolin, an exaggerated analysis unfolded steadily in the pop up of 1990s. Wild et al. [ 59 ] detailed the portlandite content at different ages through thermogravimetric
The influence of synthesis conditions on the properties of nanocrystalline boehmite catalysts was studied for styrene epoxidation
reaction in liquid phase. At hydrothermal synthesis of boehmite, effects of pH, aging time and precursor aluminum salts were
studied by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and total
surface area. Characterization results showed that boehmite samples were in the nanosize range and single-phase with high
crystallinity. Styrene epoxidation reaction in liquid phase was performed over boehmite catalysts at 80 °C in ethanol, using
30% aqueous hydrogen peroxide solution and urea + 30% aqueous hydrogen peroxide solution as oxidants. The progress of the
reaction was followed by gas chromatography (GC). Higher styrene conversion and higher epoxide selectivities were achieved
when urea was mixed with H2O2 solution. Boehmite catalyst samples aged for 8 h resulted in higher epoxide selectivities.
Authors:Huahua Zhao, Lingjun Chou, and Huanling Song
In the current paper, the metal organic coordination polymer Zn4O(OH)2(BDC)2(H2O)2.7 (Zn-MOCP) with high thermal and chemical stability was synthesized by a direct mixing method at room temperature. Then the catalyst Ni@Zn-MOCP (7.5 wt% Ni) was successfully prepared via a wet impregnation strategy employing Ni(acac)2 (acac = acetylacetonate) as the precursor. The hydrogenation of crotonaldehyde was utilized as the probe reaction to explore its catalytic activity. The samples were characterized by powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR), N2 adsorption–desorption measurements, X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). PXRD patterns of Ni@Zn-MOCP showed good coincidence with that of Zn-MOCP, and the pore texture of Zn-MOCP was still maintained after impregnation. Most of Ni(acac)2 over Zn-MOCP were reduced to Ni0 after reduction based on XPS analysis. In terms of the turnover of frequency (TOF) of crotonaldehyde, Ni@Zn-MOCP (53.6 h−1) exhibited much higher activity than the industrial catalyst Ni/SiO2 (29.5 h−1). Furthermore, the reusability of the catalyst Ni@Zn-MOCP over the hydrogenation for crotonaldehyde was tested.
Authors:Lidia Kuznetsova, Sergei Koscheev, Nina Kuznetsova, and Ludmila Detusheva
in 500 mg KBr.
UV–VIS spectra of solutions were taken on a Specord M-40 instrument in the region of 30000–11000 cm –1 using 1 mm glass cuvettes and water as a reference solution.
Thermogravimetricanalysis was performed on a Q
Authors:M. Jose John, K. Muraleedharan, V. M. Abdul Mujeeb, M. P. Kannan, and T. Ganga Devi
the same day of the pretreatment in order to avoid the possible ageing effect.
Thermogravimetric measurements in static air were carried out on a custom-made thermobalance fabricated in
collected for analysis. After the fifth recycling, the recovered catalyst was washed with methanol for three times and dried at 100 °C for 3 h. Then, the recovered catalyst was characterized by thermogravimetricanalysis and infrared spectra
Authors:Hyun-Gyu Kang, Hyunho Shin, and Gihong Kim
was first checked by thermogravimetricanalysis, and the result is shown in Fig. 1 . The ball milled powder for 24 h shows weight loss of 0.7 % as the temperature rises to about 580 °C and saturation thereafter. From the observation that the weight
with anhydrous KBr as standard. Thermogravimetricanalysis (TGA) are performed by a STA 409PC thermal gravimetric analyzer under a flowing N 2 atmosphere and the temperature ranges from 35 to 800 °C at a heating rate of 10 °C min −1