Catalytic Generation of Hydrogen from Water by Reduced Forms of 12-Tungstosilicic Acid in the Presence of Heterogeneous Rhodium Polymer Catalysts
Статья (Full article),
Russian Chemical Bulletin
, E-ISSN: 1573-9171
Andizhan Pedagogical Institute, Andizhan
Institute of Catalysis, Siberian Branch, Academy of Sciences of the USSR, Novosibirsk
Institute of Chemical Physics, Academy of Sciences of the USSR, Moscow
The reducedforms of heteropolyacids (HPA) in acidic aqueous solutions are capable of spontaneous reoxidation, releasing H2. It can be expected that the reduced forms of HPAs with negative electrochemical reduction potentials Eo (here and subsequently, relative to NHE) should also release H2 in the presence of metallic catalysts. Feasibility in principle was demonstrated for the use of colloidal Pt to catalyze the generation of H2 from solutions of reduced forms of 12-tungstosilicic HPA. In the present work, we have studied the evolution of H2 from solutions of reduced forms of this HPA in the presence of the heterogeneous Rh polymer catalyst Rh-AN-221, which is active in the reaction of hydrogen generation from acidic aqueous solutions of the one-electron reducing agents V2+(aq) and
1. A study has been made of the catalytic action of a heterogeneous rhodium-polymer catalyst on the evolution of hydrogen from water and water-alcohol solutions of weakly reduced forms of 12-tungstosilicic acid.
2. The activity of this catalyst under the conditions of the experiment is limited by diffusion of the reactant from the bulk solution.
3. It has been found that heteropolyacid ions immobilized on the polymer together with finely dispersed particles of metallic rhodium take an active part in electron transfer from the bulk solution to the metallic particles within the polymeric support, thus promoting the catalytic process.