III International Conference

PP-I-59characteristics are as follows: limiting adsorption ami,j, adsorptive factors b , standardi, joooheats Δ H ( H ) and changes of the Gibbs energy Δ G ( H ) and entropy S ( H )ai,j2ai,j2Δ ofthe adsorptions. Calculations were made for the catalytic systems, consisting of the skeletalnickel catalyst and solvents, such as aliphatic spirits, dimethylformamide, ethylacetate, theiraqueous solutions and also aqueous solutions of sodium hydroxide. Thermodynamic model ofa surface with discrete heterogeneity was used for ideal surface calculations within twoalternative schemes, considering the various formation mechanisms of atomic forms. Someresults of the calculations are listed in the table.aTable. Thermodynamic characteristics of hydrogen individual forms adsorbedfrom solutions on surface of skeletal nickel catalyst.m ,i, jcm 3 H 2 /g NiSolvent Water Ethanol 2–propanolα 1 –formγ–formβ 2 –formα 1 –formb i, j γ–form–oH ( H )Δ ,ai,jkJ/mol2β 2 –formα 1 –formγ–formβ 2 –form2,1±0,18,1±0,49,7±0,51,9±0,19,8±0,47,8±0,43,0±0,212,0±0,64,0±0,2ai,jAqueous solution ofethanol with x 2 =0,287,2±0,410,2±0,53,1±0,2327,3±16,4 125,0±6,3 120,0±6,0 48,0±2,4(9,5±0,5) . 10 5 (3,1±0,2) . 10 6 (4,4±2,0) . 10 6 (2,4±0,1) . 10 6(4,1±0,2) . 10 3 (5,9±0,3) . 10 4 (2,6±1,0) . 10 4 (1,1±0,1) . 10 326,0±1,362,0±3,1138,3±6,932,9±1,659,8±3,0138,5±6,930,9±1,550,0±2,5144,0±7,232,2±1,663,3±3,2142,5±7,1The results of calculations showed that thermodynamic characteristics of individualforms of the hydrogen depend on the nature and structure of solvents. Their influence occursthrough the changes of the limiting adsorption, adsorptive factors, standard heats of theadsorptions and also the change of entropy and normal affinity of hydrogen as a result ofstructure arrangement of a metal surface and its specific solvation by solvent. Quantitativeredistribution between individual forms of the adsorbed hydrogen, caused by the displacementof the superficial balances under action of a solvent is a principal cause of influence of thenature and structure of solvents on the laws of hydrogen adsorption on the skeletal nickelcatalyst.2112