Identification of nickel species and their interaction with the support in Ni-silica catalyst precursor

The influence of the support on the properties of nickel catalysts for edible oil hydrogenation

“…As is well known, when the nickel salt is precipitated with sodium carbonate in the presence of silica, the synthesized compound is the silica-supported basic nickel carbonate with a composition of Ni(OH) x (CO 3 ) y /SiO 2 ÁzH 2 O that varies considerably with the changes in the precipitation conditions [23,25]. The tendency of the silica support to react strongly with the Ni-containing species has been reported in several studies [24,26,27]. This strong interaction has been suggested to result in the formation of nickel hydrosilicate layers on the surface of the silica particles.…”

“…This strong interaction has been suggested to result in the formation of nickel hydrosilicate layers on the surface of the silica particles. The formed phases have been identified as nickel antigorite [26,10,27,28], nickel chrysotiles [29], nickel montomorillonite [26,28], nickel polygorskite [24], serpentine [30] or even orthosilicate-type [24]. The poorly crystallized nickel hydrosilicate compounds with imperfect nickel antigorite and/or nickel montmorillonite-like structure are always formed during the co-precipitation of nickel nitrate and alkali silicate solutions at temperature under 100 8C [28].…”

“…They are of relatively low intensity and shifted to lower wave numbers (the bands centred at 1050, 770 and 450 cm À1 ). A new band centred at 1450 cm À1 appears proving the presence of CO 3 2À ions [23,24]. SEM is used to investigate the morphology and the uniformity of the particle shape, as well as to determine the chemical homogeneity of the supports.…”

Catalytic combustion of benzene over CuO/CeO2 catalysts prepared using the precipitation–deposition method

“…Therefore, remarkable discrepancies in catalytic performance are often observed. The methods currently used include co-precipitation [8], precipitation-deposition [9], impregnation [5], and the sol-gel method [10]. In previous work, we have observed that the precipitation-deposition method can achieve a high metal loading on the support and high dispersion [9,11].…”

Effect of pretreatment conditions on the catalytic combustion of benzene over SBA-15-supported copper oxide prepared using the precipitation-deposition method

“…Several techniques are employed to obtain supported metal oxide catalysts such as: impregnation, ion-exchange and precipitation-deposition by using different precipitation agents [4][5][6]. Of the three techniques, precipitationdeposition can produce high metal loading on the support, and a high dispersion.…”