Silicon-Based Solid Acid Catalyst With High Acid Loading Stability
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Solution Overview
Problem
Current solid sulfonic acid catalysts face issues such as low acid amount, structural instability, and mechanical weakness, limiting their industrial application, while inorganic silica-sulfonic acid catalysts suffer from low surface hydroxyl groups and adsorbed acid detachment, making them inefficient for acid-catalyzed reactions.
Innovation Solution
A method involving the use of metasilicic acid with high surface hydroxyl groups, chemically bonded with sulfonating and/or phosphorylating agents to create inorganic silicon-based sulfonic and/or phosphoric acid catalysts with high acid amount and mechanical strength, avoiding structural degradation during preparation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If organic solid sulfonic acid catalyst materials (polystyrene sulfonic acid resin, perfluorosulfonic acid resin, fatty sulfonic acid strong acid cation exchange resin) are used, then the catalyst can be easily prepared and separated, but the functional groups have poor degree of freedom, the reverse reaction of sulfonation reduces service life, and the resin swells and breaks in organic solvent reaction systems causing sulfonic acid group detachment and catalyst deactivation
Solution Approach 1:
The invention combines inorganic silicon-based materials with sulfonic acid and/or phosphoric acid functional groups to create a composite catalyst material that integrates the advantages of both organic and inorganic materials, achieving high acid amount, mechanical strength, and chemical stability while avoiding the drawbacks of pure organic resin catalysts
Solution Approach 2:
The invention changes the chemical composition parameters by introducing phosphoric acid groups alongside sulfonic acid groups, and adjusts the ratio of different acid groups to optimize both the acid amount and the stability of the catalyst in organic solvent reaction systems
2Power
If inorganic silica-sulfonic acid catalysts are prepared by reacting silica gel with sulfonating agents, then the catalyst exhibits high reactivity and good selectivity, but the number of surface hydroxyl groups is too small limiting sulfonic acid group bonding, and adsorbed acid detaches after water washing making the catalyst inefficient
Solution Approach 1:
The invention changes the surface chemistry parameters of the silicon-based material by controlling the number and accessibility of hydroxyl groups, and adjusts the acid group loading density to achieve both high reactivity and high acid amount simultaneously
Solution Approach 2:
The invention uses silicon-based materials with specific surface properties as intermediaries that can strongly bind both sulfonic acid and phosphoric acid groups, preventing acid detachment while maintaining high reactivity for acid-catalyzed reactions
3Ease of manufacture
If silica gel with small number of surface hydroxyl groups is used as raw material for preparing silica-sulfonic acid, then the preparation is simple, but the amount of sulfonic acid groups bound to surface is limited and acid amount is very low (less than 0.14 mmol/g, difficult to reach 0.15-0.20 mmol/g)
Solution Approach 1:
The invention creates a composite catalyst system combining silicon-based materials with multiple acid groups (sulfonic and phosphoric acid), where the silicon-based material provides a platform with sufficient hydroxyl groups to support high acid group loading while maintaining structural integrity
Solution Approach 2:
The silicon-based material serves multiple functions: as a structural support, as a source of hydroxyl groups for acid group bonding, and as a stabilizing matrix that prevents acid group detachment, thereby enabling high acid amount while maintaining preparation simplicity
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 resulting catalysts exhibit high acid amounts (0.25-8.4 mmol/g) and mechanical strength (greater than 60N), maintaining stability and effectiveness in acid-catalyzed organic reactions.
Implementation Method 1
bonding the sulfonic acid group and/or the phosphoric acid group to the inorganic silicon material in the form of chemical bonding by a sulfonating agent and/or a phosphorylating agent
Implementation Method 2
the adsorbed acid is not covalently bonded to the silica particles... the sulfonic acid group is easy to detach off
Data Source
AI summary
A preparation method and use of a novel pure inorganic solid silicon-based sulfonic acid and/or phosphoric acid catalytic material are disclosed. The surface hydroxyl-rich metasilicic acid is used as the raw material, and by using a sulfonating reagent and/or phosphoric acid, the sulfonic acid group and/or the phosphoric acid group are bonded to the inorganic silicon material by chemical bonding to obtain a pure inorganic solid silicon-based sulfonic acid and/or phosphoric acid catalytic material. The catalytic material can be widely used in many acid-catalyzed organic reactions such as isomerization, esterification, alkylation, hydroamination of olefins, condensation, nitration, etherification, multi-component reactions and oxidation reactions. The inorganic solid silicon-based sulfonic acid and/or phosphoric acid catalytic material of the present invention has the advantages of high acid amount, high activity, good hydrothermal stability, no swelling, simple preparation, low cost, no pollution, no corrosion, easy separation and reusability.