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Instrumentation is reported for rapid, on-line quantitative analysis of the gaseous effluent from a heterogeneously catalyzed reaction. Absorption bands over the mid-infrared (IR) range 4000–580 cm−1 have been used to quantify, in less than 2 min, the major gaseous products of the hydrogenation of carbon monoxide (Fischer-Tropsch synthesis) using partial least squares (PLS) methodology. The fast analysis capability of the IR technique coupled to a single channel microreactor enables the approach of a Fischer-Tropsch catalyst to steady-state to be investigated by sampling the products every 2 min for 3 h on-stream. Coupling IR spectroscopy and chemometrics in this manner will allow a wide range of heterogeneously catalyzed reactions to be analyzed in very short times, a key requisite for high throughput catalyst testing. [Copyright &y& Elsevier]

Addressed herein is the 20+ year-old question of whether the true benzene and cyclohexene hydrogenation catalysts derived from the organometallic precursor [Rh(η5-C5Me5)Cl2]2, 1, are homogeneous or heterogeneous. The methodology employed is that developed earlier (Lin, V.; Finke, R. G. lnorg Chem. 1994, 33, 4891, "A More General Approach to Distinguishing Homogeneous from Heterogeneous Catalysis.."). The kinetic evidence especially, but also the metal product (nanoclusters plus bulk metal), Hg(0) poisoning and other experiments, provide compelling evidence that Rh(0) nanoclusters are the true benzene hydrogenation heterogeneous catalyst derived from [Rh(η5-C5Me5)Cl2]2, 1, at the required more vigorous conditions of 50-100 °C and 50 atm H2. However, the same methods reveal that the cyclohexene hydrogenation catalyst derived from 1 at the milder conditions of 22°C and 3.7 atm H2 is a nonnanocluster, homogeneous catalyst, most likely the previously identified complex, [Rh(η5-C5Me5)(H)2(solvent)J (Gill, D. S.; White, C.; Maitlis, P. M J. C. S. Dalton Trans. 1978, 617). In short, the present results solve the two- decade-old problem of identifying the true benzene and cyclohexene hydrogenation catalysts derived from [Rh(η5-C5Me5)Cl2]2. Perhaps most significant is the demonstration that the methodology employed has the ability to identify both heterogeneous and homogeneous catalysts from the same catalyst precursor. [ABSTRACT FROM AUTHOR]

Reports on [sup 13]C nuclear magnetic resonance spectroscopy that shows that the n-alkene and n-alkane products from the catalytic hydrogenation of carbon monoxide (CO) in the presence of [sup 13]C[sub 2]H[sub 4] probes over four catalysts. Effect of ethene initiator on the course of CO hydrogenation; Kinetic determination of reaction products.