Silica-Supported Catalyst Nitrate Ion Control
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Solution Overview
Problem
Existing catalysts for vapor phase catalytic oxidation and ammoxidation of propane face challenges in maintaining attrition resistance and yield due to the composition and aggregation state of the silica sol used as a carrier, with the concentration of nitrate ions in the silica sol being a critical but understudied factor.
Innovation Solution
The method involves controlling the concentration of nitrate ions in the silica sol within a specific range (10 to 270 wt ppm based on SiO2) to produce a silica-supported catalyst with improved attrition resistance and yield, achieved by adjusting the nitrate ion content during the preparation of the silica sol and incorporating it into the catalyst composition, which includes metals like molybdenum, vanadium, antimony, and niobium supported on silica.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the silica sol aggregation state is changed to improve catalyst performance, then the yield improves, but the attrition resistance deteriorates
Solution Approach 1:
The patent applies parameter changes by controlling the nitrate ion concentration in the silica sol within a specific range (10 to 270 wt ppm based on SiO2). This parameter control optimizes the aggregation state of the silica sol, simultaneously achieving high catalyst yield and excellent attrition resistance. The specific concentration range represents a precise parameter optimization that resolves the contradiction between yield and attrition resistance.
2Productivity
If the nitrate ion concentration in silica sol is increased to control aggregation state, then the catalyst performance improves, but the manufacturing complexity increases
Solution Approach 1:
The patent simplifies the manufacturing process by identifying and controlling a single key parameter - the nitrate ion concentration in the silica sol. Rather than complexing with multiple variables, the invention focuses on this specific parameter within the range of 10 to 270 wt ppm, making the manufacturing process manageable while achieving superior catalyst performance.
3Productivity
If the silica carrier composition is optimized to improve catalytic activity, then the yield increases, but the attrition resistance decreases
Solution Approach 1:
The patent creates a composite structure by incorporating nitrate ions into the silica carrier matrix at controlled concentrations. This composite approach, where nitrate ions are integrated within the silica structure, enhances catalytic activity while the silica framework maintains structural integrity and attrition resistance. The composite nature of the carrier (silica with controlled nitrate incorporation) resolves the contradiction between activity and stability.
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 silica-supported catalyst exhibits excellent attrition resistance and target product yield, maintaining initial performance over time and optimizing the catalytic activity for propane oxidation and ammoxidation reactions.
Implementation Method 1
the state of aggregation of the silica sol used as the carrier has some effect on the attrition resistance of the obtained catalyst
Implementation Method 2
an unsaturated carboxylic acid or an unsaturated nitrile can be synthesized by a vapor phase catalytic oxidation or ammoxidation reaction using an alkane as a starting raw material
Data Source
AI summary
To produce a silica-supported catalyst having an excellent yield of a target product and excellent catalyst attrition resistance. A method for producing a silica-supported catalyst comprising Mo, V, Nb, and a component X (Sb and/or Te) to be used in a vapor phase catalytic oxidation or ammoxidation of propane, comprising the steps of: (I) preparing a raw material mixture solution by mixing Mo, V, Nb, component X, a silica sol, and water; (II) obtaining a dry powder by drying the raw material mixture solution; and (III) obtaining a silica-supported catalyst by calcining the dry powder, wherein the silica sol contains 10 to 270 wt ppm of nitrate ions based on SiO2.