Nanometric Zeolite Y Preparation via Curing Silicon Addition
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Solution Overview
Problem
Current methods fail to produce FAU-structural-type zeolite Y with nanometric dimensions and a high Si/Al ratio greater than 2, which limits their catalytic performance and selectivity due to restricted diffusional paths and gradual deactivation.
Innovation Solution
A method involving the mixing of tetravalent element sources, trivalent element sources, and alkaline metal or alkaline-earth metal sources in an aqueous medium to form a gel, followed by curing and hydrothermal treatment, achieving crystallization of FAU-structural-type nanometric zeolite Y with crystal sizes less than 100 nm and an Si/Al ratio greater than 2.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional methods are used to prepare zeolite Y, then the Si/Al ratio can be increased, but the crystal size becomes too large (>100 nm), resulting in restricted diffusional paths and gradual deactivation
Solution Approach 1:
The patent applies preliminary action by adding a source of tetravalent element A (silicon source) during the curing step before hydrothermal treatment. This preliminary addition of silicon source during curing prepares the gel structure in advance to limit crystal growth, ensuring that after hydrothermal treatment the crystals remain nanometric (<100 nm) while achieving high Si/Al ratio (>2) and maintaining catalytic activity without deactivation
Solution Approach 2:
The patent applies parameter changes by modifying the curing conditions - specifically adding a silicon source during curing and controlling the curing temperature (0-50°C) and time (1-60 days). These parameter changes in the curing step fundamentally alter the crystal growth behavior, enabling production of nanometric zeolite Y with Si/Al ratio >2, which resolves the contradiction between achieving high Si/Al ratio and maintaining small crystal size for catalytic performance
2Reliability
If the Si/Al ratio is increased to improve selectivity, then catalytic performance improves, but conventional methods cannot achieve both high Si/Al ratio and nanometric dimensions simultaneously
Solution Approach 1:
The patent applies preliminary action by adding a source of tetravalent element A (silicon source) during the curing step. This preliminary silicon addition controls the Si/Al ratio to be greater than 2 while simultaneously limiting crystal growth to nanometric dimensions (<100 nm), achieving both high selectivity and precise crystal size control that conventional methods cannot accomplish
Solution Approach 2:
The patent applies parameter changes by modifying the curing parameters - adding silicon source during curing and controlling curing temperature (0-50°C) and time (1-60 days). These parameter changes enable simultaneous achievement of high Si/Al ratio (>2) for selectivity and nanometric crystal size (<100 nm) for manufacturing precision, resolving the contradiction between these two requirements
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 method produces zeolite Y with enhanced diffusion properties, improved catalytic activity, and selectivity, maintaining high crystallinity and purity, overcoming the limitations of conventional methods.
Implementation Method 1
curing of the gel that is obtained at the end of step (i) at a temperature of between −15° C. and 60° C.
Implementation Method 2
the hydrothermal treatment of the gel that is obtained at the end of step (iii) at a temperature of between 20° C. and 200° C. to achieve the crystallization of said FAU-structural-type nanometric zeolite Y
Data Source
AI summary
Preparation of a FAU-structural-type nanometric zeolite Y having a crystal size of less than 100 nm and an Si/Al ratio that is greater than 2: mixing, in aqueous medium, of at least one AO2 source of at least one tetravalent element A that is silicon, germanium, and/or titanium, at least one BOb source of at least one trivalent element B that is aluminum, boron, iron, indium, and/or gallium, at least one C2/mO source of an alkaline metal or alkaline-earth metal C that is lithium, sodium, potassium, calcium, and/or magnesium the C2/mO source also having at least one hydroxide ion source obtaining a gel, curing of the gel after at least 3 days of curing, with addition of at least one source of at least one tetravalent element A and the hydrothermal treatment of the gel obtained at a to achieve crystallization of the FAU-structural-type nanometric zeolite Y.