The b-oriented silicalite-1 membrane on the substrate α-Al2O3 pre-coated with a silica-zirconia intermediate layer was synthesized by using in-situ crystallization. The influence of chemical properties of the substra...The b-oriented silicalite-1 membrane on the substrate α-Al2O3 pre-coated with a silica-zirconia intermediate layer was synthesized by using in-situ crystallization. The influence of chemical properties of the substrate surface on crystal growth and orientation was investigated. The result indicated that the surface modification by pre-coating a thin film of chitosan was conducive to the formation of b-oriented silicalite-1 membrane with good quality.展开更多
Zeolite membranes offer great application potentials in membrane separation and/or reaction due to their excellent separation performance and catalytic ability. Up to present, various synthesis methods of zeolite mem-...Zeolite membranes offer great application potentials in membrane separation and/or reaction due to their excellent separation performance and catalytic ability. Up to present, various synthesis methods of zeolite mem- branes have been developed, including embedded method, in-situ hydrothermal synthesis method, and secondary growth method etc. Compared with the in-situ hydrothermal synthesis method, the secondary growth method possesses a variety of advantages such as easier operation, higher con- trollability in crystal orientation, microstructure and film thickness, leading to much better reproducibility. This review provides a concise summary and analysis of various synthesis methods reported in the literature. In particular, the secon- dary growth method was discussed in detail in terms of crys- tal orientation, defects and crystal grain layers. Some critical issues were also highlighted, which were conducive to the improvement in the synthesis technology of zeolite mem- branes.展开更多
The mechanical strength of solid catalysts is one of the key parameters for reliable and efficient perform-ance of a fixed bed reactor. Some recent developments and their basic mechanics within this context are review...The mechanical strength of solid catalysts is one of the key parameters for reliable and efficient perform-ance of a fixed bed reactor. Some recent developments and their basic mechanics within this context are reviewed. The main concepts discussed are brittle fracture which leads to the mechanical failure of the catalyst pellets, measurement and statistical properties of the catalyst strength data, and mechanical reliability of the catalyst pellets and their packed bed. The scientific basis for the issues on the catalyst mechanical properties calls yet for further elucidation and ad-vancement.展开更多
文摘The b-oriented silicalite-1 membrane on the substrate α-Al2O3 pre-coated with a silica-zirconia intermediate layer was synthesized by using in-situ crystallization. The influence of chemical properties of the substrate surface on crystal growth and orientation was investigated. The result indicated that the surface modification by pre-coating a thin film of chitosan was conducive to the formation of b-oriented silicalite-1 membrane with good quality.
文摘Zeolite membranes offer great application potentials in membrane separation and/or reaction due to their excellent separation performance and catalytic ability. Up to present, various synthesis methods of zeolite mem- branes have been developed, including embedded method, in-situ hydrothermal synthesis method, and secondary growth method etc. Compared with the in-situ hydrothermal synthesis method, the secondary growth method possesses a variety of advantages such as easier operation, higher con- trollability in crystal orientation, microstructure and film thickness, leading to much better reproducibility. This review provides a concise summary and analysis of various synthesis methods reported in the literature. In particular, the secon- dary growth method was discussed in detail in terms of crys- tal orientation, defects and crystal grain layers. Some critical issues were also highlighted, which were conducive to the improvement in the synthesis technology of zeolite mem- branes.
文摘The mechanical strength of solid catalysts is one of the key parameters for reliable and efficient perform-ance of a fixed bed reactor. Some recent developments and their basic mechanics within this context are reviewed. The main concepts discussed are brittle fracture which leads to the mechanical failure of the catalyst pellets, measurement and statistical properties of the catalyst strength data, and mechanical reliability of the catalyst pellets and their packed bed. The scientific basis for the issues on the catalyst mechanical properties calls yet for further elucidation and ad-vancement.
