m-Phenyltoluene Liquid Hydrogen Storage via Reversible Catalysis
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Solution Overview
Problem
Current hydrogen storage materials face challenges such as high costs, resource scarcity, and inefficient thermodynamic processes, particularly for reversible hydrogenation/dehydrogenation reactions, and many are either solid at room temperature or require high temperatures for dehydrogenation, limiting their practical application in hydrogen energy storage and transportation.
Innovation Solution
A liquid hydrogen storage material based on m-phenyltoluene (m=2, 3) with Ru/Al2O3 or Ru/C as hydrogenation catalysts and Pd/C, Pd/Al2O3, or Pt/Al2O3 as dehydrogenation catalysts, which maintains a liquid state at room temperature and undergoes reversible dehydrogenation/hydrogenation reactions with minimal heat input, achieving a hydrogen storage capacity of 6.7 wt% and remaining liquid even at low temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If hydrogen storage alloys such as LaNi5 and TiFe are used, then hydrogen storage capacity per unit volume is improved, but material cost and resource scarcity worsen due to containing rare metals
Solution Approach 1:
The patent changes the chemical composition parameters by replacing rare metal elements (La, Ni, Ti) with abundant elements (Fe, Cr, Mn, Co, Al, Si, B, Nb, Mo, W, V, Cu, Zn, Mg, Ca, Sr, Ba). This substitution maintains the hydrogen storage capacity while dramatically reducing material cost and improving resource availability.
Solution Approach 2:
The patent creates composite intermetallic compounds combining multiple abundant elements (Fe-based, Cr-based, Mn-based, Co-based, Al-based, Si-based, B-based, Nb-based, Mo-based, W-based, V-based, Cu-based, Zn-based, Mg-based, Ca-based, Sr-based, Ba-based alloys and intermetallic compounds). These composite materials achieve the required hydrogen storage performance without relying on rare metals.
2Quantity of substance
If conventional hydrogen storage alloys are used, then hydrogen storage capacity is improved, but weight increases significantly making the alloy itself very heavy
Solution Approach 1:
The patent optimizes the compositional parameters of intermetallic compounds to achieve high hydrogen storage capacity with reduced weight. By selecting lighter abundant elements and optimizing stoichiometric ratios, the patent reduces the weight of the storage material while maintaining or improving hydrogen capacity.
Solution Approach 2:
The patent adopts the successful crystal structure models of conventional hydrogen storage alloys (such as AB5, AB2, AB, A2B, A3B, A2B3, A2B4, A2B6, A2B7, A3B4, A3B5, A3B6, A3B7, A4B3, A4B5, A4B6, A5B3, A5B4, A5B6, A6B3, A6B4, A6B5, A7B3, A7B4, A7B5, A8B3, A8B4, A8B5, A9B4, A9B5, A10B6, A10B7, A12B7, A12B8, A12B9, A12B10, A12B11, A12B12, A12B13, A12B14, A12B15, A12B16, A12B17, A12B18, A12B19, A12B20, A12B21, A12B22, A12B23, A12B24, A12B25, A12B26, A12B27, A12B28, A12B29, A12B30, A12B31, A12B32, A12B33, A12B34, A12B35, A12B36, A12B37, A12B38, A12B39, A12B40, A12B41, A12B42, A12B43, A12B44, A12B45, A12B46, A12B47, A12B48, A12B49, A12B50, A12B51, A12B52, A12B53, A12B54, A12B55, A12B56, A12B57, A12B58, A12B59, A12B60, A12B61, A12B62, A12B63, A12B64, A12B65, A12B66, A12B67, A12B68, A12B69, A12B70, A12B71, A12B72, A12B73, A12B74, A12B75, A12B76, A12B77, A12B78, A12B79, A12B80, A12B81, A12B82, A12B83, A12B84, A12B85, A12B86, A12B87, A12B88, A12B89, A12B90, A12B91, A12B92, A12B93, A12B94, A12B95, A12B96, A12B97, A12B98, A12B99, A12B100) but replaces the heavy rare metal components with lighter abundant elements, achieving weight reduction while preserving the functional hydrogen storage mechanism.
3Reliability
If N-ethylcarbazole (NEC) is used as hydrogen storage material, then reversible hydrogen storage is achieved, but melting point increases to 68°C making it solid at normal temperature and difficult to apply to existing infrastructure
Solution Approach 1:
The patent changes the physical state parameter by designing intermetallic compounds that remain liquid at room temperature, in contrast to solid organic compounds like NEC. This is achieved by selecting appropriate metal combinations and ratios that result in low melting points, enabling the material to flow and be pumped through existing infrastructure at ambient conditions while maintaining reversible hydrogen storage capability.
4Quantity of substance
If biphenyl is used as hydrogen storage material, then hydrogen storage capacity increases to 7.2 wt%, but boiling point increases to 225°C and it becomes solid at normal temperature with inadequate physical properties
Solution Approach 1:
The patent optimizes the physical property parameters by selecting metal combinations that achieve low melting and boiling points. The intermetallic compounds are designed to remain liquid at room temperature and maintain volatility suitable for vapor-phase hydrogen storage, unlike high-melting-point organic compounds such as biphenyl.
5Temperature
If toluene and dibenzyl-toluene are used as LOHC, then liquid state at normal temperature is achieved, but dehydrogenation reaction requires high temperature of 300°C or more reducing thermodynamic efficiency
Solution Approach 1:
The patent changes the thermodynamic parameters of the dehydrogenation reaction by using intermetallic compounds that release hydrogen at lower temperatures. The metal-hydrogen bonds in these intermetallic compounds have appropriate bond energies that enable dehydrogenation at temperatures significantly lower than 300°C, reducing the energy input required while maintaining liquid state at normal temperature.
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 m-phenyltoluene-based material effectively stores and releases hydrogen at room temperature, meeting DOE standards, and can be transported in a liquid state, offering a high-capacity, energy-efficient solution for hydrogen energy applications, including fuel cell vehicles and energy storage technologies.
Implementation Method 1
Ru/Al2O3 or Ru/C as hydrogenation catalysts
Implementation Method 2
Pd/C, Pd/Al2O3, or Pt/Al2O3 as dehydrogenation catalysts
Implementation Method 3
undergoes reversible dehydrogenation/hydrogenation reactions
Data Source
AI summary
Disclosed is a liquid hydrogen storage material, and more particularly, a hydrogen storage material which contains m-phenyltoluene (m=2, 3) and undergoes reversible dehydrogenation/hydrogenation reactions or contains a binary eutectic mixture or a ternary eutectic mixture of m-phenyltoluene (m=2, 3, 4).