Homogeneous catalysis of the water gas shift reaction by ruthenium and other metal carbonyls. Studies in alkaline solutions

摘要: Homogeneous catalysis of the water gas shift reaction (H/sub 2/O + CO reversible H/sub 2/ CO/sub 2/) has been demonstrated for a number metal carbonyl complexes under alkaline conditions. Characterization catalysts based on ruthenium in alkaline, aqueous ethoxyethanol solution demonstrates that principal species present conditions are hydride anions 3/Ru/sub 4/(CO)/sub 12//sup -/ and HRu/sub 3/CO)/sub 11//sup -/. (The room temperature synthesis latter ion by Ru/sub 3/(CO)/sub 12/ alcoholic KOH is described). The rate shows first-order dependence both partial pressure total concentration. Cyclic mechanisms proposed to explain these observations involve nucleophilic attack or hydroxide coordinated followed decarboxylation give hydridic from which eliminated CO-assisted, rate-limiting step. It noted prepared adding iron carbonyls same more active than either ruthenium-based iron-based alone. These mixed catalyst solutions shown contain clusters, it synergetic effect catalytic activity may result greater reactivitymore » clusters toward elimination dihydrogen.« less