| The reactions of platinum and iridium cations in the ionic domains of a novel polymer, perfluorosulfonic acid (PFSA) with small gaseous molecules, like CO, ('13)CO, H(,2), D(,2), NO, C(,2)H(,2) (and N(,2)H(,4)) have been studied. The reactions were followed by infrared spectroscopic methods. The cations were introduced into the polymer by ion exchange of the hydrogen form of the polymer from an aqueous solution of the metal salts.; Two types of Pt-PFSA were prepared: one from PtCl(,2), and the other from {lcub}Pt(NH(,3))(,4)(.)Cl(,2){rcub} solution. The former is designated at Pt-PFSA-A and the latter as Pt-PFSA-B. Iridium PFSA was prepared from {lcub}Ir(NH(,3))(,5)(.)Cl{rcub}(.)Cl(,2) solution.; Reaction of Pt-PFSA-A with CO gave two types of Pt(II)-CO. One was a CO weakly (sigma)-bonded and the other a CO strongly bonded to the Pt(II)-sites. On desorption the platinum centers were reduced and a Pt(0)-CO obtained. A reaction scheme similar to the water-gas-shift reaction was proposed to explain the reduction of Pt-centers. The proposed reaction scheme was verified by reaction of the P-PFSA-A with H(,2), CO and ('13)CO. Reaction of the hydrated form of Pt-PFSA-A with C(,2)H(,2) gave a product which was similar to that obtained when Pt-PFSA-A was reacted with CH(,3)CHO.; The thermal deamination of Pt-PFSA-B, between 230-250(DEGREES)C, resulted in the removal of all the amine ligands from the platinum center, reduction of the platinum center, and reprotonation of the polymer. A thermal deamination pathway, consistent with the experimental data is proposed. Reactions of deaminated Pt-PFSA-B with CO, H(,2), NO and C(,2)H(,2) are also presented. Results of the reaction with C(,2)H(,2) and H(,2) suggest that C(,2)H(,2) is being hydrogenated to form saturated hydrocarbons over Pt-PFSA-B.; The thermal deamination of Ir-PFSA at a temperature between 230(DEGREES)C to 250(DEGREES)C resulted in a partial deamination of Ir-PFSA. Reactions of partially deaminated Ir-PFSA with H(,2), CO and C(,2)H(,2) are presented. Reaction with C(,2)H(,2) resulted in Ir-C(TBOND)CH species. Unlike the Pt-PFSA-B no saturated hydrocarbons were detected when Ir-PFSA was reacted with C(,2)H(,2) and H(,2).; The H(,2)-D(,2) exchange reaction was studied over Pt-PFSA-A, Pt-PFSA-B and Ir-PFSA. Preliminary results indicate that the H(,2)-D(,2) exchange reaction is catalyzed by these ionomers. |
