Chemisorption Studies on Supported Platinum

Solar-thermal energy conversion and storage: cyclohexane dehydrogenation. Progress report, 30 September 1977-30 June 1978

“…We have added a specially designed high pressure, high temperature valve between ball valve, G, and the gas chromatograph to drop the high reactor pressure to atmospheric in order to protect the automatic gas sampling valve on the chromatograph. 4. We have added a high pressure gauge (0-2000 psig) in series with pressure gauges P2.…”

Structure and Reactivity of a V2O5/Al2O3 Catalyst Modified with Cerium in the Oxidative Dehydrogenation of Cyclohexane

“…The ratio of oxygen uptake to the BET surface areas of the samples gave the oxygen atom site intensity. The specific surface area of the supported vanadia catalyst, S V 2 O 5 , could thus be calculated from the following equation (Gurber 1962;Reddy et al 1993): (1) where σ V 2 O 5 is the cross-sectional area of V 2 O 5 (6.7 × 10 −20 m 2 ), M V 2 O 5 is the molecular weight of vanadia and N is Avogadro's number. The fractional degree of coverage (α) of the catalyst surface is the ratio of the specific surface area of vanadia to the BET surface area of the catalyst.…”

Study of the reaction mechanisms between Pt(acac)2 and alumina surface sites

“…Many attempts have therefore been made to prepare series of catalysts with different particle sizes and size distributions as narrow as possible in order to establish meaningful relationships between size and properties. One of the methods commonly used to vary this parameter is sintering of the metallic phase at elevated temperatures under specific atmospheres [1][2][3]. Particle growth by sintering is, however, difficult to control since it involves a number of random processes, like migration, collision and coalescence of particles, or emission of surface atoms by one particle and their capture by others (see, e.g., the detailed studies of sintering processes in [4,5]).…”

“…The safest way to avoid nucleation of new particles during the refilling run is to completely inhibit any adsorption of Pt(acac) 2 on the support which necessitated the development of an appropriate surface treatment. Previous work on H 2 PtCl 6 [17,18] has shown that the interaction between precursor and surface depends critically on the nature of the surface sites.…”

“…Previous work on H 2 PtCl 6 [17,18] has shown that the interaction between precursor and surface depends critically on the nature of the surface sites. In contrast to H 2 PtCl 6 , however, little is known about the way Pt(acac) 2 interacts with alumina surfaces. van Veen et al [19] reported immediate complete decomposition of the complex on c.u.s.…”