Recent progress in dehydrogenation catalysts for heterocyclic and homocyclic liquid organic hydrogen carriers

Jo, Yeongin; Oh, Jinho; Kim, Donghyeon; Park, Ji Hoon; Baik, Joon Hyun; Suh, Young‐Woong

doi:10.1007/s11814-021-0947-5

Cited by 35 publications

(12 citation statements)

References 144 publications

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“…Recently, in the context of reversible hydrogen-storage methods, bidirectional hydrogenation–dehydrogenation (BHD) of N-heteroarenes has been identified as an important and prospective catalytic process, and therefore a great deal of attention has been paid into this process (Figure A). − Gaseous H 2 can be loaded via hydrogenation of easily handleable unsaturated N-heteroarenes and stored therein for future use; a reverse process via dehydrogenation of the hydrogenated compounds can unload the stored H 2 gas for reutilization. With N-heteroarene platforms, many unidirectional homogeneous and heterogeneous catalysts were reported, which performed either hydrogenation or dehydrogenation under high pressure and high-temperature conditions in organic solvents. − Later, bidirectional hydrogenation–dehydrogenation using a single homogeneous and heterogeneous catalyst was developed, operating still under harsh conditions and mainly in organic solvents. − Use of water as a solvent for bidirectional hydrogenation–dehydrogenation under relatively mild conditions with just a single catalyst is a current challenge, and toward this, Albrecht and co-workers, and Fischmeister and co-workers recently discovered two significant systems based on homogeneous Ir complexes (Figure B). While both the systems performed dehydrogenation in refluxing water solution, Albrecht et al’s catalyst used 5 bar H 2 pressure at 90 °C and Fischmeister et al’s catalyst used atmospheric H 2 pressure at 80 °C for the hydrogenation process.…”

Section: Introductionmentioning

confidence: 99%

Reusable Single Homogeneous Ir(III)–NHC Catalysts for Bidirectional Hydrogenation–Dehydrogenation of N-Heteroarenes in Water

et al. 2022

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Bidirectional hydrogenation–dehydrogenation (BHD) catalysis is of utmost importance in the context of hydrogen storage and reutilization. There are several systems based on carbocycles/hydrogenated carbocycles and N-heterocycles/hydrogenated N-heterocycles available for storing H2 gas via hydrogenation and extracting it via the reverse dehydrogenation. However, single bidirectional catalysts to achieve both the hydrogenation and dehydrogenation reactions are rare, especially in water as the desired reaction solvent, and therefore developing such catalysts would lead to a significant development in the area. Moreover, the reuse of homogeneous aqueous-phase BHD catalysts in additional catalytic runs would practicalize a sustainable catalyst-utilization protocol. This work reports such a development where a water-soluble homogeneous iridium catalyst efficiently performed bidirectional hydrogenation–dehydrogenation of quinoxaline- and quinoline-based heterocycles in H2O under relatively mild conditions (1 atm H2, 50 °C for hydrogenation, and 100 °C for dehydrogenation), and it could be reused for running additional reaction cycles, thereby improving the net efficiency. Further, the catalyst was found to be durable as a 40 day-old stock solution of the catalyst in water still maintained high activity. A unique ligand platform consisting of uracil-containing abnormal N-heterocyclic carbene (aNHC) around the Cp*Ir center in the catalyst enabled the desired properties such as water-solubility (required for catalyst separation/reuse), metal–ligand bifunctional activation of H2 and hydrogenated N-heterocycles (during hydrogenation/dehydrogenation), and efficient hydride delivery (during hydrogenation/dehydrogenation). The mechanistic steps, as analyzed by computational studies, underscored that the activation and release of H2 were the rate-determining steps in the hydrogenation and dehydrogenation, respectively.

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Section: Introductionmentioning

confidence: 99%

Reusable Single Homogeneous Ir(III)–NHC Catalysts for Bidirectional Hydrogenation–Dehydrogenation of N-Heteroarenes in Water

et al. 2022

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“…Moreover, according to the calculated results of activation energy, we can clearly realize that Pt ML Pd(111) is favorable for the dehydrogenation of C 12 H 20 to C 12 H 10 , while Pd ML Pt(111) is beneficial to the dehydrogenation of C 12 H 10 to C 12 H 8 , which means that the effects of the two surfaces on different reaction steps and ratecontrolled steps are different, and the reactants with aromatic rings tend to promote Pd activity. 21,28 Additionally, from the global reaction, Pd ML Pt(111) is more advantageous than Pt ML Pd(111), which is related to the stronger adsorption energy of H atom on Pd ML Pt(111) surface than that of Pt ML Pd(111). 51 Finally, we obtained the entire reaction path of the dehydrogenation of PHAN on the two surfaces, and the reaction network is presented in Figure 13.…”

Section: Reaction Mechanism Of Phan Dehydrogenationmentioning

confidence: 99%

“…For example, in the screening study of cyclohexane dehydrogenation over Al 2 O 3 -supported Pt bimetallic catalyst, the addition of Rh, Ir, and Re enhanced the activity of bare Pt(111). 21 Among them, the Pt−Rh catalyst displayed the best combination in the dehydrogenation reaction. Also, Yan et al 3 adopted the synthesis strategy of loading Pt and Sn precursors on Mg−Al support, resulting in excessive Sn inhibiting dehydrogenation activity, while Sn promoted higher selectivity due to the absence of acidic sites.…”

Section: Introductionmentioning

confidence: 99%

Crystal Facet Structure Dependence and Promising Pd–Pt Catalytic Materials for Perhydroacenaphthene Dehydrogenation

Wang,

Liu

2023

ACS Appl. Mater. Interfaces

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Designing an effective Pd−Pt catalytic material with excellent catalytic performance for perhydroacenaphthene (PHAN) dehydrogenation is a great challenge. In this work, in order to explore the crystal facet structure over the bimetallic Pd−Pt catalyst on the dehydrogenation performance of PHAN, the surface compositions of two kinds of Pd (Pt) atoms with different coverage on Pd modulated Pt (PdPt) and Pt modulated Pd (PtPd) catalysts were designed and studied by means of density functional theory (DFT). Through the investigation of the reaction path of PHAN dehydrogenation on Pd ML Pt(111) and Pt ML Pd(111) surfaces, it was found that Pd ML Pt(111) was advantageous to PHAN dehydrogenation (E a = 2.317 eV). This was attributed to a lower energy barrier, more stable dehydrogenation products, and the fact that Pd doping brought Pt(111) close to the Fermi level. Apparently, Pd modulated Pt catalyst has a broad application prospect in the dehydrogenation of PHAN. In the process of optimizing the PdPt morphology, a method for selecting the minimum active unit of PdPt catalysts with different ratios was proposed, that is, the most stable active unit: rhombus structure was determined according to the surface formation energy. Moreover, we correlated the relationship among the number of H atoms removed, adsorption energy, surface charge, activation energy, reaction energy, and surface coverage, and obtained the important parameters to predict the performance of PdPt catalyst in PHAN dehydrogenation system: surface charge and d-band center. Finally, the essential correlativity among Pd−Pt surface characteristics, catalytic PHAN activity, and adsorption energy was constructed; that is, the relationship model among d-band center, H atom, and product C 12 H 8 adsorption energy was established. This work opens a new simultaneous path to improve the catalytic performance of Pd−Pt-based catalytic materials for PHAN dehydrogenation, which can be achieved by regulating the rhombic active units of Pt modulated by Pd.

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“…Low-carbon economy has been attracting more and more attention of the countries all over the world, − and it is necessary to develop a clean and renewable energy such as hydrogen to replace traditional fossil energy and reduce carbon emissions. − In the realization of hydrogen energy utilization, hydrogen storage and transportation are the tricky aspects at present. − Although high-pressure hydrogen storage as a feasible method for hydrogen storage has been widely used in the field of hydrogen fuel cell automobiles, it still has several problems such as low hydrogen storage density and the great safety hazards to be solved . In comparison, chemical hydrogen storage methods, which can achieve hydrogen storage by reversible hydrogenation and dehydrogenation of chemical materials, are more safe and have low cost. − Among all chemical hydrogen storage methods, liquid organic hydrogen carrier (LOHC) storage is considered to most likely realize large-scale application of hydrogen storage. − Polycyclic aromatic hydrocarbons (PAHs) such as toluene and dibenzyltoluene (DBT) have a high hydrogen storage rate and are suitable for use as LOHCs due to their unsaturated six-membered rings. , However, the dehydrogenation reaction of perhydro-PAHs takes place at least at 270 °C.…”

Section: Introductionmentioning

confidence: 99%

Exploring the Dehydrogenation Reaction Pathway of Perhydro-Polycyclic Aromatic Hydrocarbons over the Pt/Al₂O₃ Catalyst as Liquid Organic Hydrogen Carriers by In Situ DRIFT

Zhou

Shi

et al. 2023

J. Phys. Chem. A

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Polycyclic aromatic hydrocarbons (PAHs) have been paid more attention as liquid organic hydrogen carriers (LOHCs) because of their high hydrogen storage, easy transportation, low price, and other advantages. Dehydrogenation is the key point of the PAH hydrogen storage. However, the dehydrogenation reaction rate of perhydro-PAHs is slow, and their pathway is still not clear. To clarify the PAH dehydrogenation pathway, three kinds of perhydro-PAHs containing six-membered rings (methylcyclohexane, perhydro-diphenylmethane, and perhydro-dibenzyltoluene) are selected, and their dehydrogenation processes over the Pt/Al 2 O 3 catalyst are carried out by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFT). It was found that the dehydrogenation in the six-membered ring started in the para position of the −CH 3 group, and then, the six-membered ring was transformed into a benzene ring gradually. Between the sixmembered rings, dehydrogenation started from the side ring, which has fewer groups.

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Recent progress in dehydrogenation catalysts for heterocyclic and homocyclic liquid organic hydrogen carriers

Cited by 35 publications

References 144 publications

Reusable Single Homogeneous Ir(III)–NHC Catalysts for Bidirectional Hydrogenation–Dehydrogenation of N-Heteroarenes in Water

Reusable Single Homogeneous Ir(III)–NHC Catalysts for Bidirectional Hydrogenation–Dehydrogenation of N-Heteroarenes in Water

Crystal Facet Structure Dependence and Promising Pd–Pt Catalytic Materials for Perhydroacenaphthene Dehydrogenation

Exploring the Dehydrogenation Reaction Pathway of Perhydro-Polycyclic Aromatic Hydrocarbons over the Pt/Al₂O₃ Catalyst as Liquid Organic Hydrogen Carriers by In Situ DRIFT

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Recent progress in dehydrogenation catalysts for heterocyclic and homocyclic liquid organic hydrogen carriers

Cited by 35 publications

References 144 publications

Reusable Single Homogeneous Ir(III)–NHC Catalysts for Bidirectional Hydrogenation–Dehydrogenation of N-Heteroarenes in Water

Reusable Single Homogeneous Ir(III)–NHC Catalysts for Bidirectional Hydrogenation–Dehydrogenation of N-Heteroarenes in Water

Crystal Facet Structure Dependence and Promising Pd–Pt Catalytic Materials for Perhydroacenaphthene Dehydrogenation

Exploring the Dehydrogenation Reaction Pathway of Perhydro-Polycyclic Aromatic Hydrocarbons over the Pt/Al2O3 Catalyst as Liquid Organic Hydrogen Carriers by In Situ DRIFT

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Exploring the Dehydrogenation Reaction Pathway of Perhydro-Polycyclic Aromatic Hydrocarbons over the Pt/Al₂O₃ Catalyst as Liquid Organic Hydrogen Carriers by In Situ DRIFT