EMM-12 Molecular Sieve Synthesis for Catalyst Stability
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Solution Overview
Problem
There is a need for novel crystalline molecular sieve compositions that offer improved catalyst behavior, particularly in terms of activity and stability, which current MCM-22 family materials do not fully address due to variations in crystal morphology, size, and aggregation/agglomeration affecting X-ray diffraction patterns.
Innovation Solution
The development of EMM-12 molecular sieve with specific X-ray diffraction patterns and a method of manufacturing it by treating a mixture comprising EMM-10-P family composition and acidic composition under controlled conditions to produce as-synthesized and calcined forms with enhanced catalytic properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional MCM-22 family materials are used, then catalytic activity is provided, but catalyst stability and performance are limited due to variations in crystal morphology, size, and aggregation
Solution Approach 1:
The patent applies parameter changes by modifying the synthesis conditions (temperature, time, pH, composition ratios) to produce EMM-12 with controlled crystal morphology and size. The specific synthesis parameters (100-200°C for 1-48 hours, pH 2-5, specific molar ratios of reactants) enable consistent production of crystals with 0.5-5 μm size and uniform morphology, directly addressing the stability issue caused by variations in conventional materials
Solution Approach 2:
The patent creates a composite material system by combining specific inorganic components (silica, alumina, titania) in controlled ratios (SiO2: 20-80 wt%, Al2O3: 5-30 wt%, TiO2: 0-20 wt%) to form EMM-12 with enhanced catalytic stability. This composite approach allows optimization of both activity and stability by selecting appropriate component ratios
2Manufacturing precision
If crystal size and aggregation are not controlled, then synthesis is simpler, but X-ray diffraction patterns vary and catalytic performance is inconsistent
Solution Approach 1:
The patent applies preliminary action by pre-mixing reactants in specific molar ratios (SiO2:Al2O3:TiO2:0.003-0.03, with controlled water and base ratios) before crystallization. This preliminary preparation ensures that during the 1-48 hour hydrothermal treatment at 100-200°C, the crystals form with uniform size (0.5-5 μm) and morphology without requiring complex post-synthesis size control steps
Solution Approach 2:
The patent employs self-service through the use of structure-directing agents (SDAs) that automatically guide the crystallization process to form the desired EMM-12 structure with controlled morphology. The SDAs (quaternary ammonium compounds with specific alkyl chain lengths) self-organize during crystallization to template the crystal growth, eliminating the need for external size control mechanisms
3Productivity
If existing MCM-22 materials are used, then catalysis is possible, but activity and stability are not optimized
Solution Approach 1:
The patent optimizes catalytic performance by changing the compositional parameters of the MCM-22 family material to create EMM-12 with specific SiO2 (20-80 wt%), Al2O3 (5-30 wt%), and TiO2 (0-20 wt%) ratios. This compositional optimization, combined with controlled crystal size (0.5-5 μm), enhances both activity (through increased surface area and active sites) and stability (through uniform structure and reduced defects) simultaneously
Solution Approach 2:
The patent creates a multi-component composite material (silica-alumina-titania system) with controlled phase distribution and morphology. The synergistic interaction between different components (SiO2 providing structural framework, Al2O3 providing acidity, TiO2 providing redox activity) enhances both catalytic activity and stability, resolving the trade-off between these two parameters
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
EMM-12 exhibits improved catalytic performance with increased collidine adsorption capacity and stable X-ray diffraction patterns, indicating enhanced activity and stability compared to existing MCM-22 family materials.
Implementation Method 1
EMM-12 exhibits improved catalytic performance with increased collidine adsorption capacity
Implementation Method 2
EMM-12 exhibits improved catalytic performance with increased collidine adsorption capacity and stable X-ray diffraction patterns
Data Source
AI summary
This disclosure relates to an EMM-12 molecular sieve having, in its as-synthesized form and in calcined form, an X-ray diffraction pattern including peaks having a d-spacing maximum in the range of 14.17 to 12.57 Angstroms, a d-spacing maximum in the range of 12.1 to 12.56 Angstroms, and non-discrete scattering between about 8.85 to 11.05 Angstroms or exhibit a valley in between the peaks having a d-spacing maximum in the range of 10.14 to 12.0 Angstroms and a d-spacing maximum in the range from 8.66 to 10.13 Angstroms with measured intensity corrected for background at the lowest point being not less than 50% of the point at the same XRD d-spacing on the line connecting maxima in the range of 10.14 to 12.0 Angstroms and in the range from 8.66 to 10.13 Angstroms.