Particle size effect of redox reactions for Co species supported on silica

Chotiwan, Siwaruk; Tomiga, H; Katagiri, Masaki; Yamamoto, Yoshihisa; Yamashita, Shohei; Katayama, Misaki; Inada, Yuji

doi:10.1016/j.jssc.2016.06.020

Cited by 7 publications

(1 citation statement)

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“…This implies that there is greater difficulty in performing total reduction to metallic Co for particles with a smaller size [23]. A more hindered CoO to Co reduction for small particles is already known, while the size does not influence the reduction from Co 3 O 4 to CoO [24,25]. H 2 O formed upon CoO reduction prevents the formation of superparamagnetic cobalt particles located predominantly in the narrow pores of the support.…”

Section: X-ray Diffraction Results (Xrd)mentioning

confidence: 99%

Co Loading Adjustment for the Effective Obtention of a Sedative Drug Precursor through Efficient Continuous-Flow Chemoselective Hydrogenation of 2-Methyl-2-Pentenal

et al. 2021

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This work presents the effect of Co loading on the performance of CNR115 carbon-supported catalysts in the continuous-flow chemoselective hydrogenation of 2-methyl-2-pentenal for the obtention of 2-methylpentanal, an intermediate in the synthesis of the sedative drug meprobamate. The Co loading catalysts (2, 6, 10, and 14 wt.%) were characterized by Brunauer–Emmett–Teller (BET) surface area analysis, transmission electron microscopy (TEM), H2 temperature-programmed reduction (H2-TPR), temperature-programmed desorption of hydrogen (H2-TPD) analysis, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy for selected samples, and have been studied as hydrogenation catalysts at different pressure and temperature ranges. The results reveal that a certain amount of Co is necessary to achieve significant conversion values. However, excessive loading affects the morphological parameters, such as the surface area available for hydrogen adsorption and the particle size, preventing an increase in conversion, despite the increased presence of Co. Moreover, the larger particle size, caused by increasing the loading, alters the chemoselectivity, favouring the formation of 2-methyl-2-pentenol and, thus, decreasing the selectivity towards the desired product. The 6 wt.% Co-loaded material demonstrates the best catalytic performance, which is related to the formation of NPs with optimum size. Almost 100% selectivity towards 2-methylpentanal was obtained for the catalysts with lower Co loading (2 and 6 wt.%).

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Section: X-ray Diffraction Results (Xrd)mentioning

confidence: 99%