US EPA

8714274 

Journal Article 

Synthesis by coprecipitation and characterisation of materials obtained from the system NiO-Al2O3-SiO2 

Elena, T; Virginia, B; Mioara, H 

1997 

1 

Key Engineering Materials
ISSN: 1013-9826
EISSN: 1662-9795 

Trans Tech Publications Ltd 

Key Engineering Materials 

132-136 

73-76 

English 

By coprecipitation method in the pH pH = 6.5 - 7.0 range five samples have been prepared. Two of them (sample A and B, respectively) have binary compositions and the others are ternary, with A:B weight ratio of 1:1, 3:1 and 1:3, respectively. Sample A is situated in NiO - SiO2 binary system and it is obtained from Ni(NO3)2 .6 SiO2 and Na2SiO3 - 32% solutions in presence of NaOH solution. Sample B belong to Al2O3 - SiO2 binary system and it is obtained by coprecipitation from Al2(SO4)3 and Na2SiO3 - 32% solutions at 50 °C in the presence Of NH4Cl. The precipitates have been washed with distilled water, dried in the temperature range 105 - 110 °C, for 6 h, and then they have been calcinated at 300, 450 and 800 °C at soaking time of 2 - 4 h. The ternary compositions are situated in the 2 NiO.SiO2 - NiO.Al2O3 - SiO2 elementary subsystem. The crystalline compounds have been identified by X-ray diffraction depending on thermally treatment. The specific surface area of powders has been determined by the Blaine method.The test of catalytic activity on optimal composition was realised in debydrogenation reaction of cyclohexane. These samples are recommended for the debydrogenation reactions of cyclanes and aromatic hydrocarbures, respectively. 

Catalyst; Coprecipitation; Dehydrogenation; Nickel oxide