Cu/ZnO-based multicomponent catalysts

Saito, M., Takeuchi, M., Watanabe, T., Toyir, J., Luo, S., Wu, J. (1997). Methanol synthesis from COj and Hj over a Cu/ZnO-based multicomponent catalyst. Energy Conversion Management 38, S403-S408. 

Catalytic performances of a typical Raney Cu based catalyst compared with those of an optimal Cu/ZnO-based multicomponent catalyst and a commercial catalyst... 

A small scale test plant with a methanol production capacity of 50 kg/day has been designed and constructed in order to examine the performance of a Cu/ZnO-based multicomponent catalyst under practical reaction conditions. The production rate of methanol over the multicomponent catalyst was around 600 g/l-cat-h under the reaction conditions of 523 K, 5 MPa, and SV=10,000h The purity of methanol produced was 99.9%. 

A practical methanol synthesis process greatly requires a high performance catalyst, which must be highly active and selective for methanol synthesis and also stable for a long period in a continuous operation. RITE and NIRE have been jointly implicated in the development of high performance methanol synthesis catalysts since 1990. We developed the Cu/ZnO-based multicomponent catalyst on the basis of the role of metal oxides contained in a Cu/ZnO-based catalyst, which were found to be highly active and selective for methanol synthesis, and also stable for a long period in continuous methanol synthesis. 

Optimization of preparation conditions and improvement of stability of Cu/ZnO-based multicomponent catalysts for methanol Synthesis from CO2 and H2... 

The preparation conditions of Cu/ZnO-based multicomponent catalysts were optimized. The temperature during copreciptation should be less than 313 K, and the removal of Na from the catalyst by washing the precipitates is most important. The addition of a small amount of silica to the catalyst greatly improved the stability of the catalyst. 

Wu, J. Luo, S. Toyir, J. Saito, M. Takeuchi, M. Watanabe, T. Optimization of Preparation Conditions and Improvement of Stability of Cu/ZnO-based Multicomponent Catalysts for Methanol Synthesis from COj and H. Catal. Today. 1998,45,215-220. 

As described here, it is understandable that the activity and selectivity of methanol synthesis over Cu-based catalysts depend upon not only the Cu dispersion but also the starting salts for preparation and the residual ions on the catalysts and their effects on the structure of active sites. As the candidate of new catalyst system for methanol synthesis, the following catalysts have been vigorously studied in recent years (1) Cu-ZnO containing new components (2) precious metal such as Pd, Pt, Au, and multicomponent catalysts containing precious metals (3) transition metal except for Cu and their complex oxides (4) homogeneous catalysts consisting of Ru, Ni, etc. 

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