STA-19C Zeolite for NOx Reduction

Solution Overview

Problem

There is a need for new molecular sieves with minor structural changes that can enhance catalytic properties, particularly for treating exhaust gases from engines to meet regulatory requirements, as existing molecular sieves may not offer sufficient improvements in catalytic activity despite minor structural modifications.

Innovation Solution

A calcined molecular sieve, STA-19C, with a GME type framework containing phosphate, is developed using structure directing agents like olig-(1,4-diazabicyclo[2.2.2]octane)-pentyl dibromide and lower alkyl amines, which are calcined to remove templates and form a distinct catalytically active composition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing molecular sieves are used with minor structural modifications, then the basic framework stability is maintained, but the catalytic activity is insufficient to meet regulatory requirements

Engineering Contradiction:

Improvecatalytic activityVSAvoidregulatory compliance

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent changes the chemical composition parameters of the molecular sieve by incorporating phosphate groups into the framework and using specific structure directing agents (oligomeric species from DABCO and trimethylamine). This compositional parameter change results in STA-19 with enhanced catalytic properties for NOx reduction, achieving regulatory compliance while maintaining framework stability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite molecular sieve structure (STA-19) that combines silicoaluminophosphate framework with phosphate groups and specific organic template remnants. This composite structure integrates multiple functional components within the framework, providing both structural stability and enhanced catalytic activity for exhaust gas treatment

Inventive Principle:

Principle #40Composite materials

2Reliability

If new structure directing agents like oligomeric species from DABCO and trimethylamine are used, then the catalytic properties are enhanced, but the manufacturing complexity increases

Engineering Contradiction:

Improvecatalytic activityVSAvoidsynthesis process

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent uses pre-synthesized oligomeric structure directing agents derived from DABCO and trimethylamine that are designed to self-assemble into the desired STA-19 framework structure. This preliminary preparation of templates with specific molecular architectures simplifies the overall synthesis process by enabling spontaneous framework formation around the pre-organized templates, reducing manufacturing complexity despite the enhanced catalytic properties

Inventive Principle:

Principle #10Preliminary action

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

STA-19C exhibits improved catalytic properties, effectively reducing NOx compounds in exhaust gases, allowing for compliance with regulatory standards by promoting selective catalytic reduction and oxidation reactions.

Implementation Method 1

A calcined molecular sieve, STA-19C, with a GME type framework containing phosphate, is developed using structure directing agents like olig-(1,4-diazabicyclo[2.2.2]octane)-pentyl dibromide and lower alkyl amines

Methodology Applied

Scientific EffectSelf-assembly: Self-Assembly

Implementation Method 2

which are calcined to remove templates and form a distinct catalytically active composition

Methodology Applied

Scientific EffectTemplating:

Implementation Method 3

which are calcined to remove templates and form a distinct catalytically active composition

Methodology Applied

Scientific EffectThermal decomposition: Pyrolysis

Implementation Method 4

STA-19C exhibits improved catalytic properties, effectively reducing NOx compounds in exhaust gases, allowing for compliance with regulatory standards by promoting selective catalytic reduction and oxidation reactions

Methodology Applied

Scientific EffectCatalysis: Catalysis

Implementation Method 5

STA-19C exhibits improved catalytic properties, effectively reducing NOx compounds in exhaust gases, allowing for compliance with regulatory standards by promoting selective catalytic reduction and oxidation reactions

Methodology Applied

Scientific EffectOxidation: Oxidation

Data Source

PatentUS10413890B2STA-19, a new member of the GME family of molecular sieve zeotypes, methods of preparation and use

Publication Date: 2019.09.17 JOHNSON MATTHEY PLC

AI summary

STA-19, a molecular sieve having a GME structure and phosphorus in the framework, is described. STA-19AP (as prepared) can have a lower alkyl amine, such as trimethylamine, and olig-(1,4-diazabicyclo[2.2.2]octane)-pentyl dibromide ([DABCO-C5]x where x represents the number of repeating units) or olig-(1,4-diazabicyclo[2.2.2] octane)-hexyl dibromide ([DABCO-C6]x) as SDAs. A lower alkyl ammonium hydroxide, such as tetrabutylammonium hydroxide (TBAOH), can be used as a pH modifier for the preparation of SAPO-STA-19. A calcined product, STA-19C, formed from STA-19AP is also described. Methods of preparing STA-19AP, STA-19C and metal containing calcined counterparts of STA-19C are described along with methods of using STA-19C and metal containing calcined counterparts of STA-19C in a variety of processes, such as treating exhaust gases and converting methanol to olefins are described.