BITS Faculty Publications
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Item Review: Hydrogen adsorption and storage through a spillover mechanism in palladium-integrated metal organic frameworks(Springer, 2025-10) Kuncharam, Bhanu Vardhan Reddy; Gupta, SureshHydrogen spillover, a mechanism involving the disassociation of molecular hydrogen on a metal catalyst and subsequent diffusion of atomic hydrogen to a support material, provides an effective approach for enhancing hydrogen adsorption and storage at ambient conditions. Among porous materials, metal organic frameworks (MOFs) stand out because of their large surface area, tunable porosity, and structural versatility. This review presents a comprehensive examination of hydrogen storage via the spillover mechanism in palladium integrated MOFs. These adsorbents demonstrate synergistic interactions between metal sites and MOF, contributing to improved hydrogen chemisorption and physisorption through spillover. Particular emphasis is placed on various Pd incorporation techniques, the influence of synthesis methods on spillover efficiency, and the physicochemical factors governing hydrogen uptake. The extent of hydrogen uptake depends strongly on the Pd loading, nanoparticle size, and the nature of the MOF support. Overloading of Pd often results in particle agglomeration, reducing the active surface area and thereby diminishing storage performance. Despite these advancements, challenges remain, particularly in achieving reproducible synthesis, optimizing Pd dispersion, and understanding the kinetics of spillover. The review highlights recent progress and critical challenges in developing Pd@MOF systems for practical hydrogen storage applications.Item Dynamic modelling and control strategy of a temperature-driven metal hydride cooling system for buildings(Elsevier, 2025-03) Verma, SaketA temperature-driven coupled metal hydride (MH) based thermal energy storage (TES) system can allow to shave and shift the peak energy demand in buildings. The high energy density and long-term (seasonal) energy storage capability are its major advantages over other energy storage methods. The dynamic nature of the MH operation, however, requires controlled hydrogen transfer between the coupled MHs at a rate needed to meet the building’s transient load. While temperature-driven MH systems are studied in the literature, their application in buildings and control are scarcely reported. This paper presents a control-based dynamic modeling of the temperature-driven coupled MH-TES system for building cooling applications. The dynamic model is developed in MATLAB® Simulink environment, considering the thermodynamic and kinetic behaviors of the MH systems. Based on a preliminary analysis of a property database of over 337 hydrides, we select around 1600 MH pairs suitable for building cooling applications. Each of these MH pairs is studied for their performance using the dynamic model, and among all, Zr0.76Ti0.24Ni1.16Mn0.63V0.14Fe0.18–Ti0.85Zr0.15Cr1.2Mn0.8 MH pair showed fast dynamics along with high coefficient of performance (COP) of 0.71. A parametric investigation is performed on this MH pair to understand the effect of operating temperatures. Finally, three proportional-integral (PI) feedback controllers are investigated to regulate the temperature, pressure and mass exchange between the coupled MH pairs. The developed PI controller is sufficiently capable of rejecting the signal noise from the hydrogen flow and internal heat exchange processes with root mean square error of 5.78 W between reference and actual cooling load.Item The development and potential of green hydrogen in India(IEEE, 2025-02) Mathur, Hitesh DattThe search for alternative fuel sources has been driven by the need for a sustainable energy future. Most current forms of energy produce vast amounts of carbon content and release it into the atmosphere. This has led to a global rise in temperature levels and is seen as the immediate threat faced by all humans. In a bid to tackle this, renewable energy and green hydrogen are seen as the leading solutions. As many countries, including India, have set goals for green hydrogen, we have conducted this study to identify what the scenario is in other countries, as well as what the scenario is in India. Our focus is on Green Hydrogen, the Hydrogen Economy, Climate Change, Production of Green Hydrogen, Hydrogen Storage, and Potential of Green Hydrogen in India.Item Hydrogen storage on MgO supported TiMgn (n = 2–6) clusters: a first principle investigation(Elsevier, 2024-08) Bandyopadhyay, DebashisThe current study explores the potential of MgO-supported finite-sized TiMgn (n = 2–6) nanoclusters as hydrogen storage materials, employing density functional theory with a spin-polarized generalized gradient approximation (GGA). These systems' structural stability and electronic characteristics reveal that supported clusters offer superior hydrogen storage capabilities compared to their unassisted counterparts. Various parameters, including cluster-adsorption energy (Eads), hydrogen-adsorption energy in supported clusters (Eads-H), HOMO-LUMO gap, vertical ionization potential (VIP), vertical electron affinity (VEA), chemical potential (μ), and chemical hardness (ɳ) are computed. Substrate support notably enhances the thermodynamic stability and chemical reactivity of the TiMg5 cluster when contrasted with the bare TiMg5 cluster. Furthermore, a remarkable increase in the gravimetric hydrogen storage density, from 1.63 wt% for bare Mg5 clusters to 3.45 wt% for bare TiMg5 clusters, reaching 5.62 wt% in the supported TiMg5 cluster system is observed. These findings indicate the substrate-supported TiMg5 cluster as a promising candidate for hydrogen storage applications.Item Hydrogen storage in Ti doped 4-6-8 biphenylene (Ti.C468): Insights from density functional theory(Elsevier, 2024-08) Bandyopadhyay, DebashisHydrogen storage exploration in carbon-based materials is pivotal for advancing energy technologies. This study employs first-principles Density Functional Theory (DFT) calculations, utilizing the PBE functional with the VASP code, to investigate the 4-6-8 biphenylene (C468) and its derivatives, a distinctive 2D carbon structure. Both pristine C468 and its titanium-decorated variants (1TiC468 and 2TiC468) are analyzed. 1TiC468 and 2TiC468 exhibit maximum hydrogen molecule accommodation of up to 12 and 24, achieving gravimetric densities of 6.713 wt% and 11.188 wt%, respectively, with adsorption energies ranging from −0.132 eV/H2 to −0.399 eV/H2. These gravimetric values align with or surpass DOE guidelines. Additionally, comparative analysis indicates enhanced hydrogen adsorption due to Ti presence in C468. Molecular dynamics (MD) and phonon dispersion studies confirm the stability of mTiC468 (m = 1 and 2) systems at 300K. These findings underscore the potential of Ti-decorated C468 as hydrogen storage candidates, expanding the applications of carbon-based materials in energy storage.Item Insights of Ti-doping on the hydrogen adsorption properties of the 2D-BeN4 monolayer: A density functional investigation(Elsevier, 2025-02) Bandyopadhyay, DebashisWe examined the hydrogen storage properties of Ti-doped 2D-Beryllonitrene (2D-BeN4) using Density Functional Theory (DFT). Bader charge analysis revealed charge transfer from titanium to BeN4 and H2 molecules. TiBeN4 and 2Ti–BeN4 complexes showed Kubas interactions, allowing the binding of multiple hydrogen molecules with average adsorption energies between −0.360 eV/H2 and -0.371 eV/H2, and desorption temperatures of 460 K and 475 K respectively, meeting DOE standards. NEB studies indicated binding energies of −2.06 eV and −2.09 eV between Ti and BeN4 in TiBeN4 and 2Ti–BeN4 respectively, which are lower than the diffusion barrier energy, suggesting that there is no possibility of hoping of Ti atom from one hexagonal caped position to another equivalent position. Spin-polarized PDOS revealed induced magnetism in TiBeN4. Calculated adsorption isotherms (H2 uptake graphs) at various pressures align with DOE norms. The electronic structure analysis highlights Ti-doped BeN4 monolayers as promising materials for hydrogen storage applications.Item Beryllium-doped single-walled carbon nanotubes with Stone-Wales defects: A promising material to store hydrogen at room temperature(Elsevier, 2017-09) Ghosh, SarbaniHydrogen storage in single-walled carbon nanotubes containing the Stone-Wales defects and doped with metal atoms (titanium and beryllium) has been studied using molecular dynamics simulations and density functional theory calculations. Although, Be is known to be toxic at high temperatures, Be-doped SWCNT shows a promising potential to exceed the DOE target at moderate temperatures and pressures. One of the major advantages of doping Be is its lower atomic weight, which increases the gravimetric storage capacity compared to SWCNTs doped with heavy-wight Ti atoms. In addition, the binding energy of Be is higher than that of Ti, which enhances the capture of hydrogen molecules. The gravimetric and volumetric storage capacities depend not only on the dopant atom but also on the location of doping. SWCNTs in which Be is doped on the octagonal ring of the Stone-Wales defects exhibits higher storage capacity than Be doped on defect-free SWCNTs. At room temperature (298 K), the storage capacity of Be-doped SWCNT containing the Stone-Wales defect exceeds the DOE target of 5.5 wt% (gravimetric) and 40 g H2/L (volumetric) at a pressure of 267 atm, which is significantly lower than that used in high pressure vessels.Item Hydrogen adsorption in pyridine bridged porphyrin-covalent organic framework(Elsevier, 2019) Ghosh, SarbaniCovalent organic frameworks (COFs), a class of carbon-based polymeric materials have the potential to be used as hydrogen adsorbent. Three dimensional (3D) COFs, due to their low density and high surface area, although have higher hydrogen adsorption, they have less stability than two dimensional (2D) COFs. Here we studied porphyrin group containing 2D COF, namely H2,P-COF for hydrogen storage using density functional theory (DFT) and grand canonical Monte Carlo (GCMC) simulations and the results were compared with the most common 2D COFs, COF-1 and COF-5. Cylindrical shaped 2D COFs where isolated unit blocks are stacked in multiple layers due to van der Waals interactions between individual layers, increase the effective surface area for hydrogen storage. A further modification has been done by bridging the inter-layer gap by pyridine molecules. Insertion of pyridine increases the separation distance of layers of 2D COFs as well as the free volume. Feasibility of the structure formation and stability of all the structures were checked using DFT study. To ensure the structural stability of bridged COFs after hydrogen loading, alternating layers of COF were bridged. Single, bi, tri and tetra -pyridine molecules were chemically bonded with the existing carbon ring present in between two C2O2B rings to form pyridine bridged H2,P-COFs. Our GCMC results show a significant increase in storage capacity which is mainly due to an increase in the free volume of the material. The highest capacity of 5.1 wt% and 20 g H2/L at 298 K and 100 bar, above the gravimetric DOE goal, has been found at room temperature for tetra-pyridine doped porphyrin COF structure.Item Hydrogen storage using novel graphene-carbon nanotube hybrid(Elsevier, 2023) Ghosh, SarbaniHydrogen storage is an active area of research particularly due to urgent requirements for green energy technologies. In this paper, we study the storage of hydrogen gas molecules in terms of physical adsorption on a carbon-based nanomaterial, i.e., a novel graphene-carbon nanotube hybrid. The novel carbon nanostructures were prepared from pristine nanotubes and graphene sheets using molecular dynamics simulations and hydrogen storage quantified in terms of gravimetric capacity was simulated using grand canonical Monte Carlo Simulations. We found the highest storage capacity of 5.90 wt% at room temperature and 100 bar with high reversibility of operationItem Moisture uptake in nanocellulose: the effects of relative humidity, temperature and degree of crystallinity(Institute for Metals Superplasticity Problems, 2021-08) Garg, Mohit; Ghosh, SarbaniHydrogen has the potential to be an alternative source of energy. However, most of the research on hydrogen storage carried out in the past is based on low temperature (<80 K) whereas storage near room temperature is desired. Here, we report room-temperature hydrogen storage capacity of defective single-walled carbon nanotubes (SWCNT) investigated using molecular dynamics simulations and density functional theory. Four different types of defective SWCNTs are considered to study room temperature hydrogen storage. We observed maximum adsorption capacity of SWCNT with 5 and 8-membered ring defects, namely, D1. The SWCNT with other three defects studied here, Stone-Wales with 5- and 7-membered ring defect (D2), 5-membered ring defect (D3), and 3-, 5- and 8-membered ring defect (D4) have negative adsorption effect compared to the defect-free SWCNT. The highest gravimetric capacity of 1.82 wt.% is found for the D1 defective SWCNT at room temperature, 298 K and 140 atm. The DFT calculations show that hydrogen adsorption strongly depends on the type of defect where the 8-membered ring has the highest adsorption energy and the 3-membered ring has the lowest adsorption energy. A combination of 5- and 8-membered defective rings can increase hydrogen adsorption significantly even at room temperature.