INVESTIGATION ON INTERACTION OF PT AND L ZEOLITES USING IN-SITU FTIR AND PROBE REACTIONS

A new in situ IR cell, which was made of metal and suitable for cataly sis research, was reported in this paper. The Pt dispersed on acidic N H(4)L zeolite exhibited ''electronic deficiency'' and did not show bvi ous dehydrogenation activity in isopropanol decomposition reaction. Bu t enhanced the conversion of isopropanol to form H2O and propene throu gh the protection for the acid sites on zeolite against deactivation b y carbonaceous overlayers. PI on KL basic zeolite, however, exhibited some electron rich and high dehydrogenation activity in isopropanol de composition. Beside, Pt/KL was very sensitive to thiophene poison in r eactions. During the process of pretreatment and reaction, the Pt on t he mixture of (Pt/KL+NH(4)L) migrated from KL to NH(4)L and resulting in that the catalytic properties of the mixture similar as that of Pt/ NH(4)L in decomposition of isopropanol. It was proved that there was a n obvious interaction between PI and L zeolites. The Pt supported was easier to become ''electronic deficiency'' than to be ''electronic ric h'', which meant that the interaction of Pt with acidic sites was stro nger than that of Pt with basic sites, which meant that, because of th e metallicity of Pt which can be electronic donor easily but difficult to be the electronic accepter.