Acta Phys. -Chim. Sin. ›› 2004, Vol. 20 ›› Issue (07): 780-784.doi: 10.3866/PKU.WHXB20040724

• Note • Previous Articles    

Sol-gel Preparation,Characterization and Hydrogenation Property of Silica Supported Ni Catalyst

Liu Ying-Xin;Wei Zuo-Jun;Chen Ji-Xiang;Zhang Ji-Yan;Li Xin-Xue;Wei Xiong-Hui   

  1. Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University,Department of Environmental Sciences, College of Environmental Sciences, Peking University, Beijing 100871;Department of Catalysis Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072
  • Received:2003-12-16 Revised:2004-03-25 Published:2004-07-15
  • Contact: Liu Ying-Xin

Abstract: A series of Ni-SiO2 aerogel and xerogel catalysts were prepared by sol-gel supercritical drying (SCD) and general drying methods using tetraethylorthosilicate (TEOS) as a precursor of silica and nickel nitrate as starting material of nickel. Water or alcohol was used as solvent. Based on the experimental results of nitrogen adsorption-desorption, XRD, temperature-programmed reduction (TPR), IR, temperature-programmed desorption of hydrogen (H2-TPD) and activity evaluation, the physical and chemical properties and catalytic performance of the catalysts for hydrogenation of m-dinitrobenzene to m-phenylenediamine were investigated. Both the Ni-SiO2 aerogel catalysts had high specific surface areas, but their catalytic activity and selectivity were low due to their small active surface areas caused by sintering of nickel crystallite. For the Ni-SiO2 xerogel catalyst that used alcohol as solvent, well-dispersed nickel particles were formed, but the strong interaction between nickel and the support made the catalyst difficult to be reduced, thus resulting in lower degree of the utilization of metal. However, the xerogel catalyst that made use of water solution exhibited the highest catalytic activity and selectivity for m-phenylenediamine attributed to its higher surface area of active nickel, over which the conversion of m-dinitrobenzene and the yield of m-phenylenediamine were up to 92.6% and 88.4%, respectively, under the conditions of 2.6 MPa and 373 K after reaction for 1 h.

Key words: Sol-gel method, Supercritical drying, Nickel catalyst, m-dinitrobenzene