Formic Acid Hydrogen Storage via Transition-Metal Hydride Catalyst
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for reversible chemical storage of hydrogen face challenges in achieving high safety standards, efficient energy use, and reduced carbon monoxide formation, particularly in the dehydrogenation of methanol, which requires high temperatures and results in carbon monoxide poisoning of electrodes.
Innovation Solution
A method involving a hydrogenation step to convert hydrogen into formic acid and methanol using a hydrogenation catalyst, followed by a dehydrogenation step that releases hydrogen and carbon dioxide from a mixture of C1-C18 alcohol, formic acid, and water in the presence of a transition-metal hydride catalyst, which is formed in situ, at reduced temperatures to minimize carbon monoxide formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If steam reforming processes are used for dehydrogenation of methanol, then hydrogen release efficiency is improved, but carbon monoxide formation increases which poisons electrodes
Solution Approach 1:
The invention changes the temperature parameter from high (200-300°C steam reforming) to low (ambient temperature dehydrogenation). This parameter change enables efficient hydrogen release while avoiding the carbon monoxide formation that occurs at high temperatures, thus resolving the contradiction between productivity and harmful factor generation
Solution Approach 2:
The invention replaces the thermal-mechanical steam reforming process with a chemical-catalytic dehydrogenation process. Instead of using high temperature and steam to drive off hydrogen, the patent uses a catalyst to facilitate direct dehydrogenation at low temperature, substituting one mechanism for another to eliminate CO formation while maintaining hydrogen release efficiency
2Speed
If high temperatures are used for dehydrogenation, then hydrogen release rate is improved, but carbon monoxide formation increases
Solution Approach 1:
The invention fundamentally changes the temperature parameter from high to low operation conditions. By conducting dehydrogenation at ambient temperature rather than high temperature, the system achieves fast hydrogen release rates through catalytic action without generating the carbon monoxide that would form under thermal conditions
3Use of energy by moving object
If conventional water electrolysis is used for hydrogen production, then energy storage capability is improved, but safety challenges arise due to highly flammable hydrogen gas storage
Solution Approach 1:
The invention introduces formic acid as an intermediary substance that stores hydrogen in a chemically bound state rather than as free gas. This intermediary form provides the energy storage capability of hydrogen while eliminating the safety hazards of flammable gas storage, as formic acid is a stable, non-flammable liquid that can be safely handled and stored
Solution Approach 2:
The invention utilizes the phase transition concept by converting hydrogen from a gaseous state (highly flammable) into a liquid-bound chemical state in formic acid (stable and safe). This phase-like transformation from gas to chemically bound liquid form enables energy storage while dramatically improving safety
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
This approach enables efficient, safe, and selective hydrogen storage and release with reduced carbon monoxide formation, achieving high catalytic activity and energy efficiency while maintaining reasonable costs and extended lifespan of the catalyst.
Implementation Method 1
converting a mixture comprising or consisting of C 1 -C 18 alcohol, formic acid and optionally water into hydrogen and carbon dioxide in the presence of a base and a transition-metal hydride catalyst
Implementation Method 2
contacting hydrogen with carbon dioxide in the presence of a hydrogenation catalyst in order to effect the storage of hydrogen by forming a mixture of formic acid and methanol
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An aspect of the disclosure relates to a method for a reversible chemical storage of hydrogen. Said method comprises a hydrogenation step in which hydrogen is converted into at least formic acid in the presence of a hydrogenation catalyst as to chemically store the hydrogen, and a (subsequent) dehydrogenation step, in which hydrogen is released from a mixture of C1-C18 alcohol, formic acid and optionally water in the presence of a transition-metal hydride catalyst. The transition-metal hydride catalyst comprises a metal-ion selected from the group consisting of Ru, Ir, Mn, Co, Mo, Fe and Rh and at least one hydride ligand coordinated to the metal-ion. Further the transition-metal hydride catalyst comprises a tridentate ligand, or one or two of a bidentate ligand, or a tetradentate PPPP-chelating ligand, which is coordinated to the metal-ion to form the transition-metal hydride catalyst.