Supported Mo–Ir Catalyst for Selective Low-Temperature Butane Hydrogenolysis
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Solution Overview
Problem
Conventional butane hydrogenolysis catalysts face challenges with high ethane selectivity and high butane conversion at high temperatures, leading to safety concerns and high capital costs due to the use of noble metals like Ir, which are not readily available and difficult to recover.
Innovation Solution
A crystalline bimetallic Mo-Ir catalyst with a specific surface area of at least 100 m2/g, attached to a support such as alumina, titania, or silica, achieves high ethane selectivity and butane conversion without organic ligands, using a Mo:Ir molar ratio of 1:3 to 4:1 and a particle size of 1 to 10 nm.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional Ir-based catalysts are used to achieve high ethane selectivity (60-70%), then the reaction requires high temperature (>300°C), but this jeopardizes reactor safety and can lead to thermal runaway
Solution Approach 1:
The patent changes the chemical composition parameters by introducing Mo as a promoter with Ir, creating a bimetallic catalyst system. This compositional change allows the reaction to proceed at lower temperatures (200-300°C) while maintaining or improving ethane selectivity, thus resolving the contradiction between selectivity and safety
Solution Approach 2:
The patent uses a composite catalyst system combining Mo and Ir metals on a support material. This composite structure synergistically enhances catalytic activity and selectivity, allowing operation at lower temperatures that prevent thermal runaway while achieving high ethane selectivity
2Manufacturing precision
If conventional Ir-based catalysts are used to achieve high ethane selectivity, then capital cost increases significantly, but Ir is not readily available and difficult to recover
Solution Approach 1:
The patent replaces expensive, scarce Ir-based catalysts with a more affordable Mo-Ir bimetallic system. By using Mo as a promoter, the catalyst achieves comparable or superior performance at lower cost, and the Mo component can be more easily sourced and potentially recovered, addressing the availability and cost issues
3Object-affected harmful factors
If organometallic clusters are used to achieve high ethane selectivity (70%) at lower temperature (215°C), then butane conversion is low (<5 wt.%)
Solution Approach 1:
The patent merges the advantages of organometallic clusters (low temperature operation, high selectivity) with the advantages of supported metal catalysts (high conversion). The Mo-Ir bimetallic composition on a support combines the synergistic electronic effects that enable low-temperature activity with the high surface area and stability needed 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 achieves ethane selectivity of at least 70% and butane conversion of 50% at 240 to 325°C, outperforming conventional Ir catalysts by 5 to 10 times in catalytic activity and maintaining safety at lower temperatures.
Implementation Method 1
A supported catalyst for hydrogenolysis of butane includes a support and a catalytic crystalline bimetallic composition that includes a molybdenum-iridium (Mo—Ir) crystalline composition attached to the support
Implementation Method 2
The catalyst can have a hydrogenolysis of butane to ethane selectivity of at least 50%, preferably 70%, most preferably 75%
Data Source
AI summary
Catalysts for the hydrogenolysis of butane are described. A supported catalyst for hydrogenolysis of butane to ethane can include a support and a catalytic crystalline bimetallic composition that can include a molybdenum-iridium (Mo—Ir) crystalline composition attached to the support. The supported catalyst has a BET specific surface area of at least 100 m2/g, preferably 100 m2/g to 500 m2/g. Method of use and methods of making the catalyst are also described.