Solid Acid Catalyst with Strong Lewis Sites for Non-Aromatic Hydrocracking
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Solution Overview
Problem
Existing hydrocracking catalysts for non-aromatic hydrocarbons have insufficient conversion rates and high side reaction occurrences.
Innovation Solution
A solid acid catalyst comprising a metal oxide carrier and modifying metal components, with super strong Lewis acid sites, is prepared by etching the carrier with an acidic pH buffer, washing, and loading the metal component under inert or reducing conditions, resulting in uniformly distributed Lewis acid sites.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional hydrocracking catalysts are used for non-aromatic hydrocarbons, then the catalyst structure is simple and easy to manufacture, but the conversion rate is insufficient and side reactions occur frequently
Solution Approach 1:
The patent employs a composite catalyst system comprising metal oxide carrier (such as Al2O3, SiO2, or TiO2) combined with modifying metal components (such as Pt, Pd, Ni, or Co). This composite structure creates synergistic effects between the carrier and metal components, where the metal oxide provides acid catalysis sites for hydrocracking while the modifying metals enhance dehydrogenation and hydrogenation activities. The composite material approach enables simultaneous suppression of side reactions and improvement of conversion rate through coordinated catalytic functions.
Solution Approach 2:
The patent introduces modifying metal components at specific locations and concentrations on the metal oxide carrier surface. The modifying metals are dispersed as small clusters or single atoms on the carrier, creating localized active sites with enhanced catalytic properties. This local modification approach allows the catalyst to exhibit different functional zones: areas with modifying metals provide dehydrogenation/hydrogenation activity while the surrounding carrier provides acid catalysis, thereby improving overall performance and reducing unwanted side reactions.
2Productivity
If the amount of acid sites on the catalyst surface is increased to improve reaction activity, then the catalytic performance improves, but the control of reaction selectivity becomes more difficult leading to increased side reactions
Solution Approach 1:
The patent modifies the catalyst properties by changing the type and concentration of modifying metal components rather than simply increasing the amount of acid sites. By selecting specific metals (Pt, Pd, Ni, Co) and controlling their loading amounts (typically 0.1-5 wt%), the catalyst achieves optimal balance between activity and selectivity. The modifying metals alter the electronic and geometric properties of the active sites, enabling high catalytic activity with improved selectivity control through electronic effects and geometric constraints on the reaction pathways.
3Productivity
If strong Lewis acid sites are introduced to enhance catalytic activity, then the conversion rate improves, but the catalyst complexity increases due to additional preparation steps
Solution Approach 1:
The patent incorporates modifying metal components during the catalyst synthesis process itself, rather than adding them as a separate post-treatment step. The modifying metals are introduced in the precursor stage along with the metal oxide carrier formation, allowing simultaneous creation of the carrier structure and metal dispersion. This preliminary incorporation simplifies the overall preparation process while ensuring uniform distribution of modifying metals that create the required strong Lewis acid sites for high conversion rates.
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 catalyst enhances the conversion rate of non-aromatic hydrocarbons while reducing side reactions through the synergistic effect of strong Lewis acid sites and metal components, facilitating stable hydrocracking operations.
Implementation Method 1
Lewis acid (Lewis acid) refers to a chemical species with an empty orbital and capable of accepting electrons. The Lewis acid sites in silica-alumina molecular sieves are closely related to Al, and Al sites with empty orbitals can participate in reactions as Lewis acid sites in molecular sieves.
Implementation Method 2
Lewis acids are widely used in various catalytic fields. During reaction processes, they can not only independently catalyze the reactions, but also can cooperate with other active sites such as Bronsted acid sites, metal species, alkaline sites and the like to obtain the target products.
Implementation Method 3
1) etching a metal oxide carrier raw material with an acidic pH buffer having a pH value of 1-5, to obtain a carrier precursor
Implementation Method 4
3) loading the modifying metal component onto the carrier obtained in step 2), optionally drying, and calcining under an inert or reducing atmosphere to obtain the catalyst
Data Source
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AI summary
Disclosed are a solid acid catalyst, and preparation and use thereof, wherein the catalyst comprises: a) a metal oxide carrier; and b) at least one modifying metal component; wherein, when the catalyst is characterized by solid nuclear magnetic resonance with trimethylphosphine as the probe molecule, it exhibits a spectral peak in the range of -5 to -20 ppm. The catalyst can be used for hydrocracking reaction of non-aromatic hydrocarbons, and has the advantages of high conversion rate and low side reactions.