Titanium-Bridged Zeolite Mesopores for Hydrocracking Selectivity
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Solution Overview
Problem
Existing zeolites lack enhanced catalytic functionality for hydrocracking reactions, particularly in terms of selectivity and stability, due to limitations in their structural properties.
Innovation Solution
The development of modified zeolites that incorporate titanium atoms bonded to four bridging oxygen atoms and feature mesopores ordered with cubic symmetry, which are synthesized through a process involving dehydroxylated zeolites, organometallic chemical grafting, and subsequent hydrogen treatment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional zeolite structures are used, then the material maintains structural simplicity, but catalytic selectivity and stability for hydrocracking reactions are insufficient
Solution Approach 1:
The patent creates a composite material by integrating titanium atoms into the zeolite framework. The titanium atoms are bonded to four bridging oxygen atoms within the microporous framework, forming a titanosilicate composite structure that combines the structural benefits of zeolite with the catalytic properties of titanium, thereby improving catalytic stability and selectivity
Solution Approach 2:
The patent applies local quality modification by strategically placing titanium atoms at specific locations within the zeolite framework. The titanium atoms are positioned to bond with four bridging oxygen atoms, creating localized active sites that enhance catalytic functionality without altering the overall framework structure, thus improving performance while maintaining structural integrity
2Manufacturing precision
If titanium atoms are incorporated into the zeolite framework, then catalytic selectivity for naphtha is improved, but the manufacturing process complexity increases
Solution Approach 1:
The patent employs preliminary action by first dehydroxylating the zeolite to create isolated terminal silanol functionalities, then grafting organometallic chemicals to form intermediate zeolites with organometallic moieties. This stepwise preliminary preparation enables precise titanium incorporation and controlled conversion to titanium hydride moieties, achieving high catalytic selectivity through controlled sequential reactions
Solution Approach 2:
The patent uses intermediary compounds in the synthesis process. Organometallic chemicals serve as intermediaries to introduce titanium into the zeolite framework, and titanium hydride moieties act as intermediaries during the conversion process. These intermediary species enable controlled titanium incorporation and transformation, achieving precise catalytic selectivity while managing process complexity through well-defined intermediate stages
3Productivity
If mesopores with cubic symmetry are created, then mass transport and accessibility are enhanced, but structural complexity increases
Solution Approach 1:
The patent introduces a new dimensional aspect by creating ordered mesopores with cubic symmetry within the zeolite framework. This three-dimensional ordered pore structure adds a mesoscale dimension to the traditional microporous zeolite structure, enabling enhanced mass transport and accessibility while maintaining overall structural organization through the cubic symmetry pattern
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 modified zeolites exhibit improved catalytic selectivity for naphtha in hydrocracking reactions, enhanced stability against air and moisture exposure, and bi-functional catalysis due to the strategic placement of titanium atoms relative to acid sites.
Implementation Method 1
reacting the organometallic chemical with the dehydroxylated zeolite forms a first intermediate zeolite comprising organometallic moieties each bonded to an oxygen atom of the intermediate zeolite
Implementation Method 2
reacting the first intermediate zeolite with hydrogen to form a second intermediate zeolite, wherein reacting the first intermediate zeolite with hydrogen converts at least a portion of the organometallic moieties to titanium hydride moieties
Implementation Method 3
reacting the second intermediate zeolite to form the modified zeolite, wherein reacting the second intermediate zeolite converts at least a portion of the titanium hydride moieties to titanium atoms bonded to four bridging oxygen atoms
Implementation Method 4
the modified zeolites described herein may have enhanced catalytic functionality for cracking hydrocarbons
Data Source
AI summary
Modified zeolites may include a microporous framework including a plurality of micropores having diameters of less than or equal to 2 nm. The microporous framework may include at least silicon atoms and oxygen atoms. The modified zeolite may include a plurality of mesopores having diameters of greater than 2 nm and less than or equal to 50 nm, wherein the plurality of mesopores are ordered with cubic symmetry. The modified zeolite may include a plurality of titanium atoms each bonded to four bridging oxygen atoms, wherein each of the bridging oxygen atoms bonded to the titanium atoms bridges one of the plurality of the titanium atoms and a silicon atom of the microporous framework.