Catalytic Reductions Using Carbon Monoxide and Water in Place of Hydrogen

Tetracarbonylhydridoferrates, MHFe(CO)4: versatile tools in organic synthesis and catalysis

“…22 For NaHFe(CO)4, the proton chemical shift is -8.74 ppm (THF solution) and this complex is distinguishable from NaHFe2(CO)8 (5 -8. 47) or from NaHFe3(CO)u (8 -14.87) under the same conditions. 44 The 13C NMR spectrum of [PPN]+[HFe(CO)4]' in CD2C12 shows a signal at 220.8 ppm for the average carbonyl chemical shift.…”

“…In this case, the reaction is only slightly exothermic and exhibits a large positive entropy change (eq 83).133 CO(g) + H20(1) ^C02(g) + H2(g) The possible use of Fe(CO)5 as a homogeneous catalyst for the water-gas shift reaction was suggested by Reppe as early as 1953. These suggestions were based on even earlier work, the publication of which had been delayed by World War II.137 A great deal of time has been devoted to the study of this reaction, 46,47,133,138 and it now appears well accepted that a simplified catalytic cycle may be represented (see Scheme XIV). 139 Under high pressure in a 75:25 methanol/water mixture, the hydrogen production was shown to be first order in iron pentacarbonyl, independent of carbon monoxide pressure, and sensitive to pH of the reaction medium.…”

“…Mechanism of Formation A great deal of interest has been devoted to the mechanism of formation of HFe(CO)4-from reaction of Fe(CO)5 with aqueous hydroxide ions. [46][47][48][49][50][51][52][53][54] The first step of the reaction involves attack of the hydroxide ion on a carbonyl ligand to give a metallocarboxylic acid (eq 9).…”

The effect of the alkali additive on the highly active Ru/C catalyst for water gas shift reaction

“…8 However, the majority of the reported systems were carried out under high CO pressures (>10 bar) and their catalytic activities were usually low. 9 Therefore, the development of Ru based heterogeneous WGS catalysts with high catalytic activity was strongly demanded. However, compared with Pt, Au based heterogeneous catalysts, the study of Ru based heterogeneous catalysts was limited, [10][11][12][13] and metal oxides such as CeO 2 , 11 Fe 2 O 3 12 were usually were used as the supports.…”

Preparation and characterization of ultrathin [Ru(CO)3Cl2]2 and [BMIM][Tf2N] films on Al2O3/NiAl(110) under UHV conditions

“…9 The relatively small number of publications on homogeneous WGS catalysis (at least in comparison to its heterogeneous counterpart) was reviewed in 2007 by Jacobs and Davis. 10 From this review it can be seen that large attention was dedicated in homogeneous WGS catalysis to transition metal carbonyls 11 and especially to ruthenium carbonyls. 12 Indeed, among the transition metal catalyst precursors tested, those containing this metal generally showed the highest activity, with RuCl 3 being among the most active.…”