Heterogeneous catalysis hydrogenation

FIGURE 6 1 A mechanism for heterogeneous catalysis in the hydrogenation of alkenes... 

OH Polybutadiene Homogeneous hydrogenation [e.g., Ni or CoAriethyl aluminum (or Ru, Rh catalysis)] heterogeneous catalysis (Raney Ni) Hydrogenated mixed 1.4- and 1,2-polybutadienes as heat-resistant polyurethane prepolymers... 

The low-temperature oxidation of hydrogen as in the cap of a lead-acid storage battery is an example of heterogeneous catalysis. It is proposed to model this reaction as if it were homogeneous ... 

Theoretically, the problem has been attacked by various approaches and on different levels. Simple derivations are connected with the theory of extrathermodynamic relationships and consider a single and simple mechanism of interaction to be a sufficient condition (2, 120). Alternative simple derivations depend on a plurality of mechanisms (4, 121, 122) or a complex mechanism of so called cooperative processes (113), or a particular form of temperature dependence (123). Fundamental studies in the framework of statistical mechanics have been done by Riietschi (96), Ritchie and Sager (124), and Thorn (125). Theories of more limited range of application have been advanced for heterogeneous catalysis (4, 5, 46-48, 122) and for solution enthalpies and entropies (126). However, most theories are concerned with reactions in the condensed phase (6, 127) and assume the controlling factors to be solvent effects (13, 21, 56, 109, 116, 128-130), hydrogen bonding (131), steric (13, 116, 132) and electrostatic (37, 133) effects, and the tunnel effect (4,... 

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