화학공학소재연구정보센터
Journal of Catalysis, Vol.168, No.2, 328-333, 1997
A New Probe Reaction for Studying the Hydrogen Spillover Phenomenon
It was found by FTIR measurement that pyridine strongly adsorbed on acid sites of ZSM-5 was hydrogenated over Pt/H-ZSM-5 (0.5 wt%) and a Pt-hybrid catalyst (a physically mixed catalyst with a weight ratio of Pt/SiO2 (2,5 wt%)/H-ZSM-5 = 1:4) to adsorbed piperidine in the presence of gaseous hydrogen at around 473 K, whereas no such phenomena were observed on either H-ZSM-5 or Pt/SiO2. The phenomenon revealed the occurrence of hydrogen spillover from Pt sites to zeolite acid sites (Bronsted and Lewis). A quantitative description of this reaction was attained by calculating and measuring the amount of zeolite acid on the basis of pyridine chemisorption and hydrogen consumption. Ln connection with this finding, the dehydrogenation of adsorbed piperidine in correlation with reverse hydrogen spillover was also observed on Pt/H-ZSM-5 catalyst in the temperature range from 623 to 723 K.