Titanium Silicalite Zeolite Synthesis to Minimize TiO2 Formation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing zeolitic materials used for propylene oxide production, such as titanium silicalite-1 (TS-1), suffer from reduced catalytic performance and selectivity due to the formation of titanium dioxide (TiO2) during synthesis, which acts as a photosensitizer and interferes with the aldol condensation process, leading to decreased efficiency.
Innovation Solution
The synthesis of titanium silicalite-1 (TS-1) is optimized by using Ti-containing compounds with an APHA color number ≤ 300, minimizing the formation of TiO2 and aldol condensation products, thereby maintaining high selectivity and catalytic performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If Ti containing alcoholate is used as precursor for TS-1 synthesis, then Ti incorporation into zeolite framework is controlled, but TiO2 extra-framework formation occurs due to polymerization tendency
Solution Approach 1:
Alcohols and ketones are introduced as intermediary substances that mediate between the Ti containing alcoholate precursor and the final zeolite structure. These intermediaries prevent direct polymerization of Ti species that would lead to TiO2 formation, while still allowing controlled Ti incorporation into the zeolite framework during synthesis.
Solution Approach 2:
The synthesis conditions are modified by changing chemical parameters - specifically adding alcohols and ketones to the reaction mixture. This alters the chemical environment during synthesis, suppressing the polymerization tendency of Ti species and reducing TiO2 formation while maintaining framework Ti incorporation.
2Reliability
If TiO2 is present in TS-1 catalyst, then photosensitization effect occurs, but catalytic performance and selectivity decrease
Solution Approach 1:
The invention addresses the harmful photosensitization effect of TiO2 by preventing its formation in the first place through controlled synthesis conditions. By using alcohols and ketones during synthesis, the harmful TiO2 extra-framework species are avoided, thereby eliminating their negative photosensitization interference while maintaining the desired catalytic framework structure.
3Productivity
If aldol condensation process is interfered with, then reaction efficiency decreases, but selectivity is maintained
Solution Approach 1:
The synthesis parameters are optimized by controlling the chemical environment with alcohols and ketones. This changes the physical-chemical parameters of the Ti species during synthesis, preventing premature condensation and TiO2 formation, thereby improving both reaction efficiency and selectivity of the final catalyst.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The optimized TS-1 catalyst achieves selectivity of ≥85% in propylene epoxidation with hydrogen peroxide, requiring lower reaction temperatures and maintaining efficiency over extended runtimes.
Implementation Method 1
TS-1 is usually hydrothermally synthesized, using a Ti containing alcoholate (alkoxide) precursor in order to get a controlled incorporation of Ti into the zeolite framework
Implementation Method 2
due to the strong polymerization tendency under aqueous conditions
Implementation Method 3
which acts as a photosensitizer and interferes with the aldol condensation process
Implementation Method 4
interferes with the aldol condensation process
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to a zeolitic material having a framework structure comprising Si, O, and Ti, obtained or obtainable from a Ti containing compound, wherein the Ti containing compound has an APHA color number of ≤ 300. In a second aspect, the invention relates to the Ti containing compound having an APHA color number of ≤ 300. A third aspect of the present invention is related to the use of the Ti containing compound having an APHA color number of ≤ 300 of the second aspect for the preparation of a zeolitic material having framework structure comprising Si, O, and Ti, as well as to a process for preparation of a zeolitic material as in the first aspect having a framework structure comprising Si, O, and Ti, wherein the zeolitic material having a framework structure comprising Si, O, and Ti, is prepared from a Ti containing compound having an APHA color number of ≤ 300 as of the second aspect. A fourth aspect of the invention is directed to a molding comprising the zeolitic material having a framework structure comprising Si, O, and Ti as of the first aspect, as well as to the use of the molding as an adsorbent, an absorbent, a catalyst or a catalyst component. A fifth aspect of the invention relates to a process for oxidizing an organic compound comprising bringing an organic compound in contact with a catalyst comprising a molding as of the fourth aspect, wherein a sixth aspect relates to propylene oxide obtained or obtainable from the process according to the fifth aspect.