Surface organometallic chemistry on metals in water : Chemical modification of platinum catalyst surface by reaction with hydrosoluble organotin complexes : application to the selective dehydrogenation of isobutane to isobutene

摘要: Abstract Surface organo-metallic chemistry on metals can be a new route to generate supported bimetallic catalysts. According previous works Pt–Sn catalysts, the reaction of tetra n-butyl-tin reduced platinum surface leads well-defined catalysts which are very active and selective in dehydrogenation isobutane into isobutene. The presence tin not only isolates atoms from each other (EXAFS) thus prevents fast deactivation by decreasing processes C–C bond cleavage but also favors regeneration under air. So far catalyst preparations were carried out either gas phase or organic solution (e.g. heptane). However, order meet industrial criteria process simplicity, there is need carry such preparation water. In this work, Pt–Sn/Al2O3 Pt–Sn/SiO2 was prepared reacting tris hydroxide surface, water atmospheric pressure hydrogen. kinetics followed measuring amount butane evolved as function time. solids obtained characterized CO, O2 H2 chemisorption electron microscopy (CTEM EDAX). Clearly, (n-Bu)3Sn(OH) reacts selectively with support, evolution butane, leading where isolated atoms. Very high selectivities (>95%) activities for isobutene it concluded that metal an alternative prepare