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- Author or Editor: V. Ostrovskii x
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Abstract
A critical review of available data on the heats of chemisorption of gases at metals is given. The effect of upward technical and procedural trends on measured results is demonstrated. The results for surfaces approached to their states occurring in catalytic processes are accentuated. Several tens of chemisorbent/gas systems are considered; a number of the results are confirmed by several independent measurements. The coverage-independence of heats of chemisorption for powders, supported catalysts, components of multi-component catalysts, and films is demonstrated; the better the techniques and procedures, the closer to zero the angle between the heat-coverage function and the abscissa. The principal conclusion on surface homogeneity of stabilized surfaces is made.
Abstract
To obtain a solution of the surface “homogeneity versus heterogeneity” problem, the results of microcalorimetric measurements of the dependences of the molar heats of chemisorption and chemabsorption of different gases on the amounts of chemisorbed or chemabsorbed gases in more than 20 gas/metal-oxide systems, in which the molar chemisorption heats are coverage-independent over rather wide ranges of the surface coverages, are presented. In order to approach the states of the metal oxide samples to those in real catalytic processes catalyzed by these oxides, the coverage dependences of the heats of chemisorption of gases at the samples were measured for a number of gas/metal-oxide systems against the chemisorbed amounts of not only the gas under study but also of another gas chemisorbed previously. The calorimetric data-set is supplemented with data obtained by other methods capable of helping to solve the surface “homogeneity versus heterogeneity” problem. These data are discussed together with the data on chemisorption in more than 40 gas/metal systems for which homogeneity of the surfaces was stated in our previous review. The entire set of the measurements was published for several decades by about 40 different composite authors. The chemisorption and chemabsorption mechanisms are discussed. It is concluded that thermally stabilized powder metal and metal oxide surfaces are homogeneous relative to the chemical ability of their atoms in chemisorption and catalytic processes in line with Langmuir's opinion and the band theory of solids.
Hydrate hypothesis of living matter origination (LOH-hypothesis)
Thermodynamic grounds of formation of living matter simplest elements from hydrocarbons and niter
Abstract
In the context of the LOH-hypothesis, the following questions are discussed: (1) Could N-bases and riboses originate from CH4-hydrocarbons and niter at the expense of internal energy? (2) How had methane-hydrate originated? (3) How had CH4 and NO3 − met together? (4) Why are DNA and RNA monomer links similar and limited in size? (5) Why were N-bases and riboses limited in their chemical growth? (6) Why are the sequences of N-bases in DNA and RNA molecules not random? (7) Why do DNA and RNA compositions usually contain only five chemical elements? (8) Why do only five N-bases usually enter the DNA and RNA compositions, and why are other ones random? (9) Could D-ribose, desoxy-D-ribose, thymine, and uracil be simultaneously produced in the reaction of niter with methane? (10) Why did Nature select D-riboses for DNA and RNA construction?
