Effect of hydrogen spillover on the hydrogenation of 1-hexene over diluted carbon molecular sieve supported Pt catalyst

摘要

Pt supported on a carbon molecular sieve(Pt/CMS)was prepared by pyrolysis of polyfurfuryl alcohol containing pre-reduced Pt particles.The catalysts were characterized by hydrogen chemisorption,XRD,N_2 adsorption/desorption and TEM.Hydrogen chemisorption showed that not all the Pt particles were exposed to H2 molecules.Oxidation treatment made Pt particles more accessible to H2.Catalyst activity was evaluated by hydrogenation of 1-hexene.Hydrogen spillover was demonstrated by diluting Pt/CMS with activated carbon or hydrogen type zeolite Y.The initial conversion of 1-hexene was increased from 86.5% to 98.5% and to 100% when Pt/CMS was diluted with activated carbon and hydrogen type zeolite,respectively.The high initial conversion was sustained for 6 h in the presence of diluents while the conversion decreased quickly for Pt/ CMS alone.