Acta Phys. -Chim. Sin. ›› 1991, Vol. 7 ›› Issue (06): 721-724.doi: 10.3866/PKU.WHXB19910617

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Probe Into NH3-TPD Curve of Ni-Containing Zeolite Out The View of Acidity

Xiao Shu-Yong; Yao Jie; Meng Zhong-Yue   

  1. Department of Chemistry, Nanjing Normal University, Nanjing 210024
  • Received:1990-06-25 Revised:1991-01-28 Published:1991-12-15
  • Contact: Xiao Shu-Yong

Abstract: Two peaks, appeared respectively at Ca. 900 K and 800 K on the NH_3-TPD curve of Ni-containing Y zeolite, have been investigated. These two peaks can't be simply explained by means of acidity.
One peak observed at Ca. 90O K, has been contributed to the water gas resulted from the dehydroxylation of zeolite. Another peak, appeared at Ca. 800 K, has been proved to be due to NH_3, formed by decomposation of a complex with the suggested formula Ni~(2+)(NH)_x(OH~-)_(6-x). This complex resulted from the interaction of adsorbed NH_3, the supported Ni~(2+) species and the skeleton OH groups under suitable conditions and decomposed at Ca. 800 K by a first order reaction with an activation energy of about 90.74 kJ·mol~(-1).

Key words: Zeolite, Supported Ni species, NH3-TPD