NiCeOx Aerogel Catalyst Suppresses Methane in Water-Gas Shift
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Nickel-based catalysts for the water-gas shift reaction tend to produce methane as a byproduct, which is undesirable, and they also suffer from sintering issues at high temperatures.
Innovation Solution
A composition comprising an oxide-based aerogel with cerium and nickel (NiCeOx) is developed, where nickel is atomically dispersed within the ceria lattice, preventing the formation of discrete nickel phases and thus reducing methane production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If nickel-based catalysts are used for the water-gas shift reaction, then CO conversion is achieved, but methane is produced as an undesirable byproduct
Solution Approach 1:
The patent applies local quality by creating specific surface sites on the CeO2 aerogel with controlled oxygen vacancies and crystal facets that selectively promote WGS reaction while suppressing methanation. The aerogel's hierarchical pore structure provides different local environments: mesopores for reactant access and micropores for selective product formation, achieving high CO conversion without methane byproduct
Solution Approach 2:
The patent uses composite materials by combining Ni catalyst particles with CeO2 aerogel support to create a synergistic system. The CeO2 aerogel provides high surface area, oxygen storage capacity, and specific crystal facets that promote water activation and CO conversion while suppressing methane formation. The composite structure allows Ni to catalyze WGS reaction while the aerogel matrix prevents unwanted side reactions
2Productivity
If high temperature is used to improve reaction kinetics, then CO conversion rate increases, but catalyst sintering occurs
Solution Approach 1:
The patent applies parameter changes by utilizing the temperature-dependent redox properties of CeO2, which can store and release oxygen at different temperatures. The aerogel's high surface area and oxygen vacancy concentration allow it to maintain catalytic activity at lower temperatures (200-400°C) where sintering is minimized, while still achieving good conversion rates through enhanced surface reactivity and oxygen mobility
3Productivity
If conventional Ni catalysts are used, then WGS reaction proceeds, but catalyst durability is reduced due to sintering at high temperatures
Solution Approach 1:
The patent employs porous materials by using CeO2 aerogel with hierarchical pore structure (mesopores and micropores) as catalyst support. The high porosity and surface area provide abundant active sites for WGS reaction while the three-dimensional network structure prevents Ni particle aggregation and sintering, maintaining catalyst durability and activity over extended operation periods
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 NiCeOx aerogel catalyst effectively suppresses methane formation during the water-gas shift reaction, achieving high CO conversion rates at lower temperatures without producing detectable methane, thereby improving the efficiency and selectivity of the reaction.
Implementation Method 1
NiCeOx aerogels for methane suppression in the water-gas shift reaction
Implementation Method 2
nickel is atomically dispersed within the ceria lattice, preventing the formation of discrete nickel phases and thus reducing methane production
Data Source
AI summary
An oxide-based aerogel having cerium and nickel may be used as a water-gas shift reaction catalyst without producing methane as a byproduct. It may be made by forming a gel from a cerium salt and a nickel salt solution and converting the gel to an aerogel.