Nickel-Copper Alloy Catalyst with Eggshell Structure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing nickel-based catalysts for selective hydrogenation of polyunsaturated compounds require higher nickel content and have limitations in activity and selectivity due to uniform nickel distribution, and are prone to sulfur poisoning, which affects their service life.
Innovation Solution
A catalyst comprising a nickel-copper alloy supported on alumina, where nickel is distributed both on the crust and core of the support, with a specific preparation process involving hydrothermal treatment and the use of organic additives, enhancing nickel reducibility and resistance to sulfur poisoning, allowing for lower nickel usage and improved activity and selectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If nickel is uniformly distributed in the support, then the catalyst structure is simple, but the activity and selectivity are limited and higher nickel content is required
Solution Approach 1:
The patent applies local quality by creating an eggshell catalyst where nickel is concentrated in a crust at the periphery of the support rather than uniformly distributed. This non-uniform distribution places the active phase where it is most needed for selective hydrogenation, improving activity and selectivity while reducing overall nickel content.
Solution Approach 2:
The catalyst structure is segmented into distinct regions: a support core and a peripheral crust containing the nickel active phase. This segmentation separates the structural function (support) from the catalytic function (crust), optimizing both while reducing metal usage.
2Productivity
If nickel content is increased to improve activity, then catalyst activity increases, but cost increases and sulfur poisoning risk increases
Solution Approach 1:
By concentrating nickel in a peripheral crust rather than distributing it uniformly, the patent achieves high catalytic activity with lower overall nickel content. The local concentration of active phase at the reaction interface maximizes efficiency while reducing total metal usage and associated costs.
Solution Approach 2:
The patent uses a lower amount of expensive nickel metal while maintaining catalyst performance. The eggshell structure allows sufficient activity with reduced metal content, effectively replacing a portion of the expensive active phase with cheaper support material.
3Productivity
If nickel is used for selective hydrogenation, then high activity is achieved, but the catalyst is prone to sulfur poisoning and service life is reduced
Solution Approach 1:
The patent introduces copper as an intermediary element that preferentially interacts with sulfur-containing compounds in the feedstock. Copper acts as a sacrificial component that protects the nickel active phase from sulfur poisoning, extending catalyst service life while maintaining activity.
Solution Approach 2:
The patent converts the harmful effect of sulfur in the feedstock into a beneficial protective mechanism. Sulfur compounds preferentially react with copper instead of nickel, and this interaction is harnessed to protect the main active phase. The copper-nickel alloy structure transforms the sulfur poisoning threat into a selective protection mechanism.
4Productivity
If conventional reduction conditions are used for nickel catalysts, then nickel is reduced to active metal, but severe conditions are required and reaction time is long
Solution Approach 1:
The patent changes the chemical composition parameters by forming a copper-nickel alloy, which fundamentally alters the reduction behavior. The alloy structure enables reduction at lower temperatures and shorter times compared to pure nickel, improving process efficiency and reducing energy consumption.
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 high activity and selectivity in selective hydrogenation reactions with reduced nickel content, maintaining performance and extending service life by effectively capturing sulfur-containing compounds, enabling less severe operating conditions and shorter reaction times.
Implementation Method 1
a nickel-copper alloy supported on alumina, where nickel is distributed both on the crust and core of the support
Implementation Method 2
enhancing nickel reducibility
Implementation Method 3
effectively capturing sulfur-containing compounds
Implementation Method 4
selective hydrogenation of polyunsaturated compounds
Implementation Method 5
high activity and selectivity in selective hydrogenation reactions
Data Source
AI summary
Nickel and copper catalyst, and an alumina support:nickel distributed both in the core of and on a crust at the periphery of the support, crust thickness being 2% to 15% of catalyst diameter;nickel density ratio between the crust and the core greater than 3;crust contains more than 25% by weight of nickel element relative to total weight of nickel in the catalyst;mole ratio between nickel and copper is 0.5 to 5,at least one portion of nickel and copper is a nickel-copper alloy;nickel content in the nickel-copper alloy is 0.5% to 15% by weight of nickel element relative to total weight of the catalyst;size of the nickel particles in the catalyst is less than 7 nm.