Reversible Hydrogen Research Articles

Reversible Hydrogen Acceptor–Donor Enables Relay Mechanism for Nitrate‐to‐Ammonia Electrocatalysis

Electrocatalytic nitrate reduction is a crucial process for sustainable ammonia production. However, to maximize ammonia yield efficiency, this technology inevitably operates at the potentials more negative than 0 V vs. RHE, leading to high energy consumption and competitive hydrogen evolution. To eradicate this issue, hydrogen tungsten bronze (HxWO3) as reversible hydrogen donor‐acceptor is partnered with copper (Cu) to enable a relay mechanism at potentials positive than 0 V vs. RHE, which involves rapid intercalation of H into HxWO3 lattice, prompt de‐intercalation of the lattice H and transfer onto Cu, and spontaneous H‐mediated nitrate‐to‐ammonia conversion on Cu. The resulting catalysts demonstrated a high ammonia yield rate of 3332.9±34.1 mmol gcat−1 h−1 and a Faraday efficiency of ~100 % at 0.10 V vs. RHE, displaying a record‐low estimated energy consumption of 17.6 kWh kgammonia−1. Using these catalysts, we achieve continuous ammonia production in an enlarged flow cell at a real energy consumption of 17.0 kWh kgammonia−1.

‘Rigid–flexible’ strategy for high-strength, near-room-temperature self-healing, photo-thermally functionalised lignin-reinforced polyurethane elastomers

Lignin is the most abundant and only renewable aromatic polymer in nature. Herein, a flexible matrix and the rigid lignin were rationally integrated to prepare high-strength, near-room-temperature self-healing, processable lignin-reinforced polyurethane elastomers (LZPUs). Reversible hydrogen and oxime–amino ester bonds were introduced into the matrix to provide excellent dynamic properties and abundant ligands for lignin–matrix coordination bonds. Abundant metal coordination bonds were constructed between the matrix and lignin via the introduction of Zn2+, which not only effectively enhances the dispersibility and compatibility, but also provides an excellent energy dissipation mechanism for the LZPUs. One of the prepared elastomers, LZPUs, exhibited a high strength of 40.5 MPa, which is twice that of the blank sample and 1.6 times that of the sample without Zn2+. It maintained kinetic stability at mild temperature, but it exhibited a self-healing efficiency of 91.3 % in strength and 99.8 % in elongation at break after decoupling with trace ethanol (≈ 50 μL) at 35 °C. It exhibited a self-healing efficiency of 93.6 % in strength under 1 sun irradiation (0.1 W cm−2) for 4 h. We believe this elastomer offering high mechanical properties with multi-functionality can be applied in flexible drives and photo-thermal power generation.

The 2-Propanol Fuel Cell: Direct CO2-Free Electrification with a Liquid Hydrogen Carrier

Molecular hydrogen is a gas at ambient conditions and requires compression or cryogenic liquefaction for storage and transport, leading to significant losses in efficiency. Therefore, liquid hydrogen carriers are desirable as they are storable without losses. One such fuel that has shown promise recently is 2-propanol (isopropanol), which is converted with high selectivity to acetone in a fuel cell.[1],[2],[3] Power densities over 200 mW/cm2 have been reported for direct isopropanol fuel cells (DIFCs), which rivals the best direct methanol fuel cells (DMFCs), and unlike methanol, isopropanol is non-toxic and it is not fully oxidized to CO2. [4] The literature has demonstrated many advantages of DIFCs, yet significant challenges remain.[5] Continuous operation at high current densities can be limited due to anodic catalyst layer network effects: slow removal of acetone from active sites and out of the catalyst layer. Additionally, perfluorinated sulfonic acid (PFSA) ionomers are not fully chemically compatible with 2-propanol and acetone. Operation at higher temperatures with a vaporized 2-propanol feed partially mitigates both of these disadvantages, yet the high energy cost of vaporization reduces the overall efficiency of the system. Future research should focus on stable, high-power operation with a liquid 2-propanol feed.This contribution chronicles the progress that has been made and discusses the current state-of-the-art and outlook of direct electrification with DIFCs. Recent advances in liquid-fed DIFCs are presented, including design of membrane-electrode-assemblies and operation strategies in full cells. Finally, the concept of using the 2-propanol/acetone couple as an electrochemical liquid organic hydrogen carrier is briefly introduced: a reversible hydrogenation and dehydrogenation cycle for storing and releasing molecular hydrogen on demand.

Field-free magnetic rotation in FePd alloy films controlled by reversible hydrogenation

In this study, we performed magneto-optical Kerr effect (MOKE) microscope measurements and X-ray diffraction to examine the hydrogenation effect on the magnetic anisotropy (MA) of Fe40Pd60/Al2O3 thin films and its correlation with crystalline structure. The change in magnetic coercivity was observed and attributed to the rotation of MA, which is characterized by the azimuthal angle-dependent MOKE. Hydrogen-enhanced magnetic moment was confirmed by X-ray magnetic circular dichroism. Multi-step etching processes were used to lower the thickness of the FePd alloy coating, and the hydrogenation process triggered the magnetic easy axis to always be parallel to the same direction. The magnetic anisotropy energy (MAE) of FePd film originates from the volume and the interface-contributed MAE. When the MAEs prefer different orientations, the film thickness and the hydrogen absorption will change the dominant term, resulting in the MA rotation. Furthermore, the reversible rotation of magnetism was achieved through hydrogen absorption and desorption without an external magnetic field. These observations are applicable to the development of field-free switched spintronic devices.

Highly Stretchable, Fast Self-Healing, Self-Adhesive, and Strain-Sensitive Wearable Sensor Based on Ionic Conductive Hydrogels.

Conductive hydrogels integrate the conductive performance and soft nature, which is like that of human skin. Thus, they are more suitable for the preparation of wearable human-motion sensors. Nevertheless, the integration of outstanding multiple functionalities, such as stretchability, toughness, biocompatibility, self-healing, adhesion, strain sensitivity, and durability, by a simple way is still a huge challenge. Herein, we have developed a multifunctional chitosan/oxidized hyaluronic acid/hydroxypropyl methylcellulose/poly(acrylic acid)/tannic acid/Al3+ hydrogel (CS/OHA/HPMC/PAA/TA/Al3+) by using a two-step method with hydroxypropyl methylcellulose (HPMC), acrylic acid (AA), tannic acid (TA), chitosan (CS), oxidized hyaluronic acid (OHA), and aluminum chloride hexahydrate (AlCl3·6H2O). Due to the synergistic effect of dynamic imine bonds between CS and OHA, dynamic metal coordination bonds between Al3+ and -COOH and/or TA as well as reversible hydrogen, the hydrogel showed excellent tensile property (elongation at break of 3168%) and desirable toughness (0.79 MJ/m3). The mechanical self-healing efficiency can reach 95.5% at 30 min, and the conductivity can recover in 5.2 s at room temperature without stimulation. The favorable attribute of high transparency (98.5% transmittance) facilitates the transmission of the optical signal and enables visualization of the sensor. It also shows good adhesiveness to various materials and is easy to peel off without residue. The resistance of the hydrogel-based sensors shows good electrical conductivity (2.33 S m-1), good durability, high sensing sensitivity (GF value of 4.12 under 1600% strain), low detection limit (less than 1%), and short response/recovery time (0.54/0.31 s). It adhered to human skin and monitored human movements such as the bending movements of joints, swallowing, and speaking successfully. Therefore, the obtained multifunctional conductive hydrogel has great potential applications in wearable strain sensors.

Reversible hydrogenation and dehydrogenation of benzene for hydrogen storage on highly dispersed Pd/γ-Al2O3 catalyst

The research and development of efficient catalyst is the key to achieving high-capacity hydrogen storage in liquid organic hydrogen carriers (LOHCs). The highly dispersed Pd/γ-Al2O3 catalysts with few-atom Pd were prepared by impregnation method using HNO3 as promoter. The hydrogen storage capacity of the benzene/cyclohexane hydrogen carriers was further investigated by vapor phase benzene hydrogenation and cyclohexane dehydrogenation reactions over the studied Pd/γ-Al2O3 catalysts. The results showed that the metal Pd was the active centers for the benzene hydrogenation/cyclohexane dehydrogenation reactions. The addition of HNO3 can effectively promote the metal Pd to be highly dispersed, thus improving the Pd atoms utilization and reducing the Pd dosage. Meanwhile, the strongly electronic effects between the highly dispersed Pd species and the Al2O3 support promoted the electron-deficient Pdδ+ sites to be formed, which enhanced the adsorption and activation ability for the reactants molecules. The benzene conversion on the Pd/γ-Al2O3 catalyst with a metallic Pd loading of 1.0 wt% reached 97.51 % at 200 °C. While the cyclohexane conversion reached 90.94 % at 400 °C with the actual hydrogen storage capacity of 6.54 wt%, which provided an effective idea for large-scale storage and transportation of H2 based on LOHCs.

Sequential co-reduction of nitrate and carbon dioxide enables selective urea electrosynthesis

Despite the recent achievements in urea electrosynthesis from co-reduction of nitrogen wastes (such as NO3−) and CO2, the product selectivity remains fairly mediocre due to the competing nature of the two parallel reduction reactions. Here we report a catalyst design that affords high selectivity to urea by sequentially reducing NO3− and CO2 at a dynamic catalytic centre, which not only alleviates the competition issue but also facilitates C−N coupling. We exemplify this strategy on a nitrogen-doped carbon catalyst, where a spontaneous switch between NO3− and CO2 reduction paths is enabled by reversible hydrogenation on the nitrogen functional groups. A high urea yield rate of 596.1 µg mg−1 h−1 with a promising Faradaic efficiency of 62% is obtained. These findings, rationalized by in situ spectroscopic techniques and theoretical calculations, are rooted in the proton-involved dynamic catalyst evolution that mitigates overwhelming reduction of reactants and thereby minimizes the formation of side products.

Self-healing polyurethane composite films loaded with Ni@C nanoparticles

Widely employed as polymers, polyurethanes also struggle to strike a balance between mechanical and self-healing qualities. Extrinsic self-healing can readily result in the production of material defects and stress concentration, which can result in the loss of mechanical property. In this study, self-healing and mechanical properties were combined to create a self-healing polyurethane nanocomposite film (PUHN) with good fatigue resistance. Reversible hydrogen and disulfide bonds were introduced to the polyurethane film, meanwhile, carbon-coated nickel nanoparticles were dispersed into the matrix as fillers during the early stage of polymerization. The results showed that PUHN combines outstanding mechanical properties with excellent self-healing properties, while the tensile strength of PUHN was increased by 38 % to 2.32 MPa due to the small-size effect caused by the introduction of nanoparticles. The introduction of reversible disulfide bonding and the presence of abundant hydrogen bonding give PUHN excellent self-healing properties, which can reach 91.2 % self-healing efficiency after 3 h in an oven at 80℃. Meanwhile, the fatigue resistance of the composite material also shows considerable application potential for use in packaging.

HER Kinetics of Pt and Ni in Alkaline Medium at Elevated Temperatures (25-200 ºC) and Pressures (1-50 bar)

The hydrogen evolution reaction (HER) in alkaline medium is of great importance for the economic production of sustainable hydrogen. Nevertheless, the origin of the sluggish reaction kinetics observed in alkaline compared to acidic environment, remains a point of debate. [1-5] In order to promote understanding, and to extend the discussion at conditions closer to industrial operation, we have undertaken a systematic determination of the HER kinetics on Pt and Ni within a broad range of temperatures (25-200 ⁰C) and pressures (1-50 bar) in alkaline environment using 1 M or 10 M aqueous KOH as electrolyte.At present, the study of HER at high temperatures and pressures (HTP) is limited by the interim stability and lifetime of the available reference electrodes [6, 7]. We have overcome this limitation by employing a novel design for a Palladium hydride (PdH) and a reversible hydrogen (RHE) reference electrodes that enable facile and stable utilization at HTP [8]. A constant electrochemically driven supply of H2 on the PdH surface ensures preservation of the mixed (α+β)-phase in the PdH layer and thereby stable potential at HTP conditions for prolonged periods. Furthermore, the potential of the PdH reference electrode has been calibrated as a function of temperature and pressure with respect to the reversible hydrogen electrode (RHE). The potential of the PdH electrode in the mixed (α+β)-phase is ~55 mV vs. the RHE at 25 ⁰C, 1 bar, and observed to be independent of temperature and pressure.As shown in Figure 1, the HER kinetics are faster on Pt relative to Ni and become more sluggish on both metal surfaces upon increasing KOH concentration from 1 to 10 M at 25 ⁰C, 1 bar. A more pronounced thermal activation is observed in 10 M versus 1 M KOH though, resulting in a reversal of the pH trend at 100 ⁰C, 1 bar. References Sheng, M. Myint, J. G. Chen, Y. Yan, Energy Environ. Sci., 6, 1509–1512 (2013).Ledezma-Yanez, W. D. Z. Wallace, P. Sebastián-Pascual, V. Climent, J. M. Feliu, M. T. M. Koper, Nature Energy, 2, 17031–17037 (2017).Rossmeisl, K. Chan, E. Skúlason, M. E. Björketun, V. Tripkovic, Catalysis Today, 262, 36–40 (2016).Subbaraman, D. Tripkovic, D. Strmcnik, K. Chang, M. Uchimura, A. P. Paulikas, V. Stamenkovic, N. M. Markovic, Science, 334, 1256–1261 (2011).Liu, J. Li, L. Jiao, H. T. T. Doan, Z. Liu, Z. Zhao, Y. Huang, K. M. Abraham, S. Mukerjee, Qingying Jia, J. Am. Chem. Soc., 141, 3232−3239 (2019).H. Miles, G. Kissel, P. W. T. Lu, S. Srinivasan, J. Electrochem. Soc., 123, 332–336 (1976).J. Appleby, G. Crepy, J. Jacquelin, Int. J. Hydrog. Energy, 3, 21–37 (1978).P. Leuaa, C. Chatzichristodoulou, J. Electrochem. Soc., 169, 054534 (2022). Figure 1: (a) HER overpotential versus current density (normalized by the electrochemically active surface area) on Pt and Ni at 25 ⁰C, 1 bar, in 1 and 10 M KOH, and (b) temperature evolution of the HER overpotential at 10 mA/cm2 (normalized by the electrochemically active surface area) for Pt and Ni at 25-100 ⁰C, 1 bar, in 1 and 10 M KOH. Figure 1

Thermochemical properties of benzyltoluenes and their hydro- and perhydro-derivatives as key components of a liquid organic hydrogen carrier system

Benzyltoluenes can be utilized for hydrogen storage through reversible hydrogenation in form of pure regioisomers or as isomeric mixture. For the design of the process and in-depth understanding of the reaction, knowledge about the thermochemical properties of the different chemical species is mandatory. This work aims at providing data on relevant thermochemical properties such as vapor pressure, enthalpy of vaporization and enthalpy of formation for benzyltoluenes and their hydro- and perhydro-derivatives forming the respective liquid organic hydrogen carrier (LOHC) system. Combustion calorimetry has been utilized to determine enthalpy of reaction and high-level quantum chemical methods have been applied for validation. It has been found that the different steps of the reaction and reactions of different isomers are similar as expected, but there are still clear differences. For instance, enthalpy of reaction is higher for the hydrogenation of the meta isomer than for the other two isomers. Hydrogenation of the first ring is more exothermal than hydrogenation of the second ring and hydrogenation of the less substituted ring is more exothermal than hydrogenation of the higher substituted ring. These findings shed new light on kinetic observations, which so far have only been explained by steric effects.

Core-Shell Nano-Cobalt Catalyzed Chemoselective Reduction of N-Heteroarenes with Ammonia Borane.

An easily prepared core-shell heterogeneous nanocobalt catalyst was reported, which could achieve selective reduction of N-heteroarenes with ammonia borane under mild conditions and ambient atmosphere. Various quinoline, quinoxaline, naphthyridine, isoquinoline, acridine, and phenanthroline derivatives were hydrogenated with high selectivity and efficiency. Notably, substrates bearing sensitive functional groups under molecular hydrogen reduction conditions, such as cyano, ester, and halogens were well tolerated by the catalytic system. Moreover, with our novel method several bioactive molecules were prepared. Also, this catalyst could be applied in the liquid organic hydrogen storage system by reversible hydrogenation and dehydrogenation of heteroarene in high efficiencies.

Acceptorless dehydrogenation of 1-phenylethanol using Pd/TiO2 catalysts prepared by sol immobilisation

Reversible hydrogenation and acceptorless dehydrogenation of organic molecules would enable pre-existing technologies and infrastructure to be leveraged for the storage and transport of hydrogen. We report the synthesis of active Pd/TiO2 catalysts prepared by sol immobilisation for the acceptorless dehydrogenation of 1-phenylethanol to acetophenone with evolution of molecular hydrogen. The catalyst converts 1-phenylethanol with a TOF of 3600 mol1-PE h−1 molPd−1 while maintaining high selectivity (>95%) at over 80% conversion. This represents a 3.5 x increase in catalytic activity with comparable selectivity over commercially available 5% Pd/C catalysts.

The effects of alumina morphology and Pt electron property on reversible hydrogenation and dehydrogenation of dibenzyltoluene as a liquid organic hydrogen carrier

The morphologies and the electron property of catalysts play the very important roles in the hydrogenation and dehydrogenation of liquid organic hydrogen carriers (LOHCs) such as dibenzyltoluene (DBT). The different morphologies and pore structures of γ-Al2O3 and MoxC doped γ-Al2O3 were synthesized as the supports for Pt catalysts. After analyzing of various characterizations and catalytic testing, it was found that the large surface area and the mesoporous structure of catalysts are beneficial to both DBT hydrogenation and perhydro-dibenzyltoluene (H18-DBT) dehydrogenation. The doping of MoxC promoted the formation of the smaller Pt nanoparticles and increased Pt dispersion. The forming Pt–Mo structure is beneficial to hydrogen spillover which suppress the formation of by-product. The high Pt dispersion of 0.1 wt% MoxC doped Pt/Al2O3 catalyst plays the positive roles in increasing H18-DBT dehydrogenation activity.

Large transport gap modulation in graphene via electric-field-controlled reversible hydrogenation

Graphene is of interest in the development of next-generation electronics due to its high electron mobility, flexibility and stability. However, graphene transistors have poor on/off current ratios because of the absence of a bandgap. One approach to introduce an energy gap is to use hydrogenation reaction, which changes graphene into insulating graphane with sp3 bonding. Here we show that an electric field can be used to control conductor-to-insulator transitions in microscale graphene via a reversible electrochemical hydrogenation in an organic liquid electrolyte containing dissociative hydrogen ions. The fully hydrogenated graphene exhibits a lower limit sheet resistance of 200 Gohm/sq, resulting in graphene field-effect transistors with on/off current ratios of 10^8 at room temperature. The devices also exhibit high endurance, with up to one million switching cycles. Similar insulating behaviours are also observed in bilayer graphene, while trilayer graphene remains highly conductive after the hydrogenation. Changes in the graphene lattice, and the transformation from sp2 to sp3 hybridization, is confirmed by in-situ Raman spectroscopy, supported by first-principles calculations.

Reversible hydrogenation and irreversible epoxidation induced by graphene oxide electrolysis

Electrochemical (EC) reduction of graphene oxide (GO) serves as a green chemistry pathway to produce reduced GO (rGO). However, the mechanistic understanding of this process is still limited due to the structural complexity of GO-based materials. In the present study, we employ an inductive approach that consists of investigating the structures afforded by alternating EC reduction and oxidation steps to elucidate the electrochemical reduction reactions in aqueous solution. The initial EC reduction of chemically derived GO mainly converts epoxides (C–O–C) to COH/CH pairs. Simultaneously, carbon-centered radicals (C•) are eliminated. Subsequent EC oxidation does not result in restoration of epoxides but reverse dehydrogenation and radical formation. The second EC reduction and oxidation cycle involves reversible C–H formation coupled with radical elimination, suggesting that C• serves as an active site for the hydrogenation. As a result of this study, COH–CH is revealed as a plausible characteristic structure in electrochemically derived rGO. The reversible radical hydrogenation reaction can offer an effective route to manipulate the chemical reactivities of GO-based materials. We demonstrate that the electrons transferred by EC reduction can delocalize in the rGO to some extent, activating the pseudocapacitance that probably originates from COH.

Combining Incompatible Processes for Deracemization of a Praziquantel Derivative under Flow Conditions

AbstractAn efficient deracemization method for conversion of the racemate to the desirable (R)‐enantiomer of Praziquantel has been developed by coupling incompatible racemization and crystallization processes. By a library approach, a derivative that crystallizes as a conglomerate has been identified. Racemization occurs via reversible hydrogenation over a palladium on carbon (Pd/C) packed column at 130 °C, whereas deracemization is achieved by alternating crystal growth/dissolution steps with temperature cycling between 5–15 °C. These incompatible processes are combined by means of a flow system resulting in complete deracemization of the solid phase to the desired (R)‐enantiomer (98 % ee). Such an unprecedented deracemization by a decoupled crystallization/racemization approach can readily be turned into a practical process and opens new opportunities for the development of essential enantiomerically pure building blocks that require harsh methods for racemization.

Combining Incompatible Processes for Deracemization of a Praziquantel Derivative under Flow Conditions.

An efficient deracemization method for conversion of the racemate to the desirable (R)-enantiomer of Praziquantel has been developed by coupling incompatible racemization and crystallization processes. By a library approach, a derivative that crystallizes as a conglomerate has been identified. Racemization occurs via reversible hydrogenation over a palladium on carbon (Pd/C) packed column at 130 °C, whereas deracemization is achieved by alternating crystal growth/dissolution steps with temperature cycling between 5-15 °C. These incompatible processes are combined by means of a flow system resulting in complete deracemization of the solid phase to the desired (R)-enantiomer (98 % ee). Such an unprecedented deracemization by a decoupled crystallization/racemization approach can readily be turned into a practical process and opens new opportunities for the development of essential enantiomerically pure building blocks that require harsh methods for racemization.

Reversible hydrogenation and dehydrogenation of N-ethylcarbazole over bimetallic Pd-Rh catalyst for hydrogen storage

• Develop a bimetallic Pd-Rh catalyst for both hydrogenation and dehydrogenation reaction. • The catalyst structure that Rh clusters isolated by the surrounding Pd atoms was proved by various ex- and in-situ characterizations. • The mechanism of NEC hydrogenation was proposed and verified by DFT calculations. Hydrogen is a promising candidate to replace the exhausting fossil fuels. However, it is still a big challenge for hydrogen storage. Liquid organic hydrogen carrier (LOHC), which possesses high safety and purity, easy transport and reversibility, is highly attractive for hydrogen storage. Herein we report a new reusable bimetallic Pd-Rh nanoparticles (NPs) catalyst with synergy effect, boosting both the hydrogenation of N-ethylcarbazole (NEC) and dehydrogenation of dodecahydro-N-ethylcarbazole (12H-NEC), which allows multiple cycles of reversible high-weight% hydrogen storage and uptake in short reaction time. Various ex- and in-situ characterizations evidenced that the superior activity was attributed to the bimetallic Pd-Rh NPs cluster structure on the surface of γ-Al 2 O 3 support. The mechanism of NEC hydrogenation over the Pd-Rh catalyst was proposed and verified by density functional theory (DFT) calculations. Such a strategy can be extended to other LOHCs and sheds light onto the development of LOHCs as energy vectors.

Fabrication of Pt/WO3 Films for Visible Hydrogen Sensing at Room Temperature

Pt/WO3 thin film on borosilicate glass is applied for reversible visible hydrogen sensing. The hydrogen concentration dependent film transmittance changed from 82% (transparent) to 43% (blue) upon ...

Charge Transport Study of in-Situ Cesium Doped Monolayer Graphene

Modifying graphene with surface adsorbates is a widely studied way of modifying graphene’s electronic properties. Different graphene/adatom systems have shown that it is possible to open a band gap in graphene1, engineer topological insulators2 and create magnetic moments3. The atomic thickness of graphene maximizes the effect of adsorbates, enabling chemical sensors that achieve single molecule sensitivity4. Alkali metal adatoms are a particularly efficient dopant for graphene due to their high electronegativity. Lithium/graphene systems have been studied for in the context of low-dimensional superconductivity5 and achieving ultrafast diffusion of lithium6 for battery applications.However, doping graphene with alkali metal adatoms bears challenges. Experiments with alkali metals must be conducted in an ultra-high vacuum or inert gas environment due to the high reactivity of the alkali. Alkali metal adsorbed graphene is not air stable, which imposes limits on the available characterization methods. An impurity free graphene surface must be achieved prior to adsorption to achieve efficient adsorption and avoid unwanted parasitic reactions. This problem is particularly acute for graphene samples prepared by the use of polymer handles. Alkali metal atoms can also intercalate under the graphene layer depending on substrate and sample preparation conditions. Moreover, it is possible for adatoms to form clusters on graphene surface7which negatively impacts both doping uniformity and efficiency.In this work, we report a new method of alkali doping of graphene to reach ultra-high doping (~1014cm-2) for charge transport studies beyond the limit of ionic liquid gating. We work with chemical vapor deposition grown graphene transferred onto quartz substrates. Quartz is the substrate of choice due to its chemical inertness and optical transparency, with the latter enabling non-invasive Raman spectroscopy through the substrate. Micron scale graphene devices were prepared using lithography-based methods and the samples were thermally annealed in a nitrogen glove box environment to desorb water prior to alkali doping. The graphene was subsequently exposed to cesium vapor at different temperatures using a flip-chip method that allows hermetic sealing of the air sensitive samples in an inert gas environment with a liquid cesium source of cesium vapour. We measured the in-situ variation of graphene resistivity as cesium atoms are adsorbed onto the graphene surface, and resistivity is modulated by charge transfer doping. Evidence of ultra-high doping is shown via Raman spectroscopy performed through the quartz substrate window, with G-peak shifts from 1589 cm-1 up to 1608 cm-1. Hall measurements in-situ further confirm the strong doping. We measured the electronic transport properties of cesium doped graphene at temperatures as low as 1.2 K and under magnetic fields up to 7 T. Weak-localization, magnetoresistance and Hall resistance are measured and analyzed. 1. Elias, D. C.; Nair, R. R.; Mohiuddin, T. M.; Morozov, S. V.; Blake, P.; Halsall, M. P.; Ferrari, A. C.; Boukhvalov, D. W.; Katsnelson, M. I.; Geim, A. K.; Novoselov, K. S., Control of graphene's properties by reversible hydrogenation: evidence for graphane. Science 2009, 323 (5914), 610-3.2. Weeks, C.; Hu, J.; Alicea, J.; Franz, M.; Wu, R., Engineering a Robust Quantum Spin Hall State in Graphene via Adatom Deposition. Physical Review X 2011, 1 (2).3. Hong, X.; Zou, K.; Wang, B.; Cheng, S. H.; Zhu, J., Evidence for spin-flip scattering and local moments in dilute fluorinated graphene. Phys Rev Lett 2012, 108 (22), 226602.4. Schedin, F.; Geim, A. K.; Morozov, S. V.; Hill, E. W.; Blake, P.; Katsnelson, M. I.; Novoselov, K. S., Detection of individual gas molecules adsorbed on graphene. Nat Mater 2007, 6 (9), 652-5.5. Profeta, G.; Calandra, M.; Mauri, F., Phonon-mediated superconductivity in graphene by lithium deposition. Nat Phys 2012, 8 (2), 131-134.6. Kühne, M.; Paolucci, F.; Popovic, J.; Ostrovsky, P. M.; Maier, J.; Smet, J. H., Ultrafast lithium diffusion in bilayer graphene. Nat Nanotechnol 2017, 12, 895.7. Fan, X.; Zheng, W. T.; Kuo, J. L.; Singh, D. J., Adsorption of single Li and the formation of small Li clusters on graphene for the anode of lithium-ion batteries. ACS Appl Mater Interfaces 2013, 5 (16), 7793-7.