Publications

With the move to a hydrogen-based primary steel production envisioned for the near future in Europe existing regional industrial clusters loose major assets. Such a restructuring of industries may result in a new geographical distribution of the steel industry and also to another quality of vertical integration at sites. Both implications could turn out as drivers or barriers to invest in new technologies and are thus important in respect to vertical integration of sites and to regional policy. This paper describes an approach to model production stock invest for the steel industries in North-Western Europe. Current spatial structures are reproduced with capacity technical and energy efficiency data on the level of single facilities like blast furnaces. With the model developed both investments in specific technologies and at specific production sites can be modelled. The model is used to simulate different possible future scenarios. The case with a clear move to hydrogen-based production is compared to a reference scenario without technological shift. The scenarios show that existing trends like movement of production to the coast may be accelerated by the new technology but that sites in the hinterland can also adapt to a hydrogen economy. Possible effects of business cycles or a circular economy on regional value chains are explored with a Monte-Carlo analysis.

A vision of hydrogen based economy and clean sustainable fossil fuels-free world inspires the scientific community to put much effort into the development of visible-light-driven photochemistry and efficient solar energy harvesting. The unique features of plasmonic nanomaterials such as capability of significant electric field amplification an extreme local heating generation of high energy charge carriers and broad tunability of optical properties coupled to catalytically active surfaces provide an exciting opportunity for hydrogen production with solar photochemistry. This review sums up recent progress in the development of plasmonic thermophotocatalysis paying particular attention to sustainable production of hydrogen. We approach the subject from a broad bottom-up perspective beginning with the brief description of plasmon-related phenomena and plasmon-assisted photochemistry through the demonstration of various plasmonic nanostructures their synthesis and hydrogen production efficiency ending with the idea of continuous-flow reactors and their future implementation in hydrogen production by plasmonic thermophotocatalysis. Finally we summarize the review and highlight the remaining challenges that have to be faced before the widespread commercialization of this technology.

Concentration and velocity measurements are crucial for developing and validating hydrogen jet models which  provide  scientific  bases  for hydrogen  safety  analyses.  The  concentration   fields  have  been visualized and accurately measured using laser diagnostic methods based on lase Rayleigh and Raman scattering  techniques.  However  the  velocity  measurements  are  more   challenging.  Particle  image velocimetry (PIV) has been commonly used for measuring velocities in turbulent flows by seeding tracer particles into the flow and assuming the particles intimately following the flow.  However sometimes the  particle  seeding  is  difficult  or  disturbs  the   flow.  Moreover simultaneously  concentration  and velocity measurements are very difficult when using PIV systems to measure the velocities. Therefore the optical flow velocimetry (OFV) method was used to resolve the velocity fields from the scalar fields or  particle  images  of  hydrogen   jets.  In the  present  work  the  velocity  field  and  particle  images  of hydrogen  jets   were  simulated  using  FLUENT  with  the  large  eddy simulation (LES)  model  and  the particle images were then used to resolve the velocity field by the OFV method. The OFV results were compared with the CFD simulations to verify their accuracy. The results show that the OFC method was an  efficient  low-cost  way  to  extract the  velocity  fields  from  particle  images.  The OFV  method accurately  located  the  large  vortices  in  the  flow  and  the  velocity distribution of  the  high-velocity gradients regions was consistent with the CFD results. The present study lays a foundation for using the OFV  method  to directly  resolve  the  velocity fields from  the  concentration  fields  of  hydrogen  jets measured by laser diagnostics.

The first applications of hydrogen in a natural gas grid will be the admixing of low concentrations in an existing distribution grid. For easy quality and process control it is essential to monitor the hydrogen concentration in real time preferably using cost effective monitoring solutions. In this paper we introduce the use of a platinum based hydrogen sensor that can accurately (at 0.1 vol%) and reversibly monitor the concentration of hydrogen in a carrier gas. This carrier gas that can be nitrogen methane or natural gas has no influence on the accuracy of the hydrogen detection. The hydrogen sensor consists of an interdigitated electrode on a chip coated with a platinum nanocomposite layer that interacts with the gas. This chip can be easily added to a gas sensor for natural gas and biogas that was already developed in previous research. Just by the addition of an extra chip we extended the applicability of the natural gas sensor to hydrogen admixing. The feasibility of the sensor was demonstrated in our own (TNO) laboratory and at a field test location of the HyDeploy program at Keele University in the U.K

Chromium poisoning of the air electrode is a primary degradation mechanism for solid oxide cells (SOCs) operating under fuel cell mode. Recent experimental findings show that reversed pulse operation for SOCs operated as electrolyser cells can reverse this degradation and extend the lifetime. Here we use a multiphysics model of an SOC to investigate the effects of reversed pulse operation for alleviating chromium poisoning of the air electrode. We study the effects of time fraction of the operation under fuel cell and electrolysis modes cyclic operation starting after a certain duration and fuel cell and electrolysis current densities on the cell lifetime total power and hydrogen production. Our modeling shows that reversed pulse operation enhances cell lifetime and total power for all different cases considered in this study. Moreover results suggest that the cell lifetime total power and hydrogen production can be increased by reversed pulse operation at longer operation times under electrolysis mode cyclic operation starting from the beginning and lower electrolysis current densities. All in all this paper documents and establishes a computational framework that can serve as a platform to assess and quantify the increased profitability of SOCs operating under a co-production operation through reversed pulse operation.

In its new report Making the Hydrogen Economy Possible: Accelerating clean hydrogen in an electrified economy the ETC outlines the role of clean hydrogen in achieving a highly electrified net-zero economy. The report sets out how a combination of private-sector collaboration and policy support can drive the initial ramp up of clean hydrogen production and use to reach 50 million tonnes by 2030.<br/>Clean hydrogen will play a complementary role to decarbonise sectors where direct electrification is likely to be technologically very challenging or prohibitively expensive such as in steel production and long-distance shipping. The report highlights how critical rapid ramp-up of production and use in the 2020s is to unlock cost reductions and to make mid-century growth targets achievable.<br/>This report is part of the ETC’s wider Making Mission Possible Series – a series of reports outlining how to scale up clean energy provision within the next 30 years to meet the needs of a net-zero greenhouse gas emissions (GHG) economy by mid-century. The reports in the series analyse and set out specific actions required in the next decade to put this net-zero by 2050 target within reach.

The development of visible-light-responsive photocatalysts with high efficiency stability and eco-friendly nature is beneficial to the large-scale application of solar hydrogen production. In this work the production of biosynthetic ternary ZnCdS photocatalysts (Eg = 2.35–2.72 eV) by sulfate-reducing bacteria (SRB) under mild conditions was carried out for the first time. The huge amount of biogenic S²⁻ and inherent extracellular proteins (EPs) secreted by SRB are important components of rapid extracellular biosynthesis. The ternary ZnCdS QDs at different molar ratios of Zn2+and Cd2+ from 15:1 to 1:1 were monodisperse spheres with good crystallinity and average crystallite size of 6.12 nm independent of the molar ratio of Cd²⁺ to Zn²⁺. All the ZnCdS QDs had remarkable photocatalytic activity and stability for hydrogen evolution under visible light without noble metal cocatalysts. Especially ZnCdS QDs at Zn/Cd = 3:1 showed the highest H₂ production activity of 3.752 mmol·h⁻¹·g⁻¹. This excellent performance was due to the high absorption of visible light the high specific surface area and the lower recombination rate between photoexcited electrons and holes. The adhered inherent EPs on the ZnCdS QDs slowed down the photocorrosion and improved the stability in photocatalytic hydrogen evolution. This study provides a new direction for solar hydrogen production.

Nowadays the integration of multi-energy carriers is one of the most critical matters in smart energy systems with the aim of meeting sustainable energy development indicators. Hydrogen is referred to as one of the main energy carriers in the future energy industry but its integration into the energy system faces different open challenges which have not yet been comprehensively studied. In this paper a novel day-ahead scheduling is presented to reach the optimal operation of a hydrogen-based energy hub based on a stochastic multi-attribute decision-making approach. In this way the energy hub model is first developed by providing a detailed model of Power-to-Hydrogen (P2H) facilities. Then a new multi-objective problem is given by considering the prosumer’s role in the proposed energy hub model as well as the integrated demand response program (IDRP). The proposed model introduces a comprehensive approach from the analysis of the historical data to the final decision-making with the aim of minimizing the system operation cost and carbon emission. Moreover to deal with system uncertainty the scenario-based method is applied to model the renewable energy resources fluctuation. The proposed problem is defined as mixed-integer non-linear programming (MINLP) and to solve this problem a simple augmented e-constrained (SAUGMECON) method is employed. Finally the simulation of the proposed model is performed on a case study and the obtained results show the effectiveness and benefits of the proposed scheme.

Hydrogen is often viewed as an important energy carrier in a future decarbonized world. Currently most hydrogen is produced by steam reforming of methane in natural gas (“gray hydrogen”) with high carbon dioxide emissions. Increasingly many propose using carbon capture and storage to reduce these emissions producing so-called “blue hydrogen” frequently promoted as low emissions. We undertake the first effort in a peer-reviewed paper to examine the lifecycle greenhouse gas emissions of blue hydrogen accounting for emissions of both carbon dioxide and unburned fugitive methane. Far from being low carbon greenhouse gas emissions from the production of blue hydrogen are quite high particularly due to the release of fugitive methane. For our default assumptions (3.5% emission rate of methane from natural gas and a 20-year global warming potential) total carbon dioxide equivalent emissions for blue hydrogen are only 9%-12% less than for gray hydrogen. While carbon dioxide emissions are lower fugitive methane emissions for blue hydrogen are higher than for gray hydrogen because of an increased use of natural gas to power the carbon capture. Perhaps surprisingly the greenhouse gas footprint of blue hydrogen is more than 20% greater than burning natural gas or coal for heat and some 60% greater than burning diesel oil for heat again with our default assumptions. In a sensitivity analysis in which the methane emission rate from natural gas is reduced to a low value of 1.54% greenhouse gas emissions from blue hydrogen are still greater than from simply burning natural gas and are only 18%-25% less than for gray hydrogen. Our analysis assumes that captured carbon dioxide can be stored indefinitely an optimistic and unproven assumption. Even if true though the use of blue hydrogen appears difficult to justify on climate ground

In which way and in which sectors will renewable energy be integrated in the German Energy System by 2030 2040 and 2050? How can the resulting energy system be characterised following a −95% greenhouse gas emission reduction scenario? Which role will hydrogen play? To address these research questions techno-economic energy system modelling was performed. Evaluation of the resulting operation of energy technologies was carried out from a system and a business point of view. Special consideration of gas technologies such as hydrogen production transport and storage was taken as a large-scale and long-term energy storage option and key enabler for the decarbonisation of the non-electric sectors. The broad set of results gives insight into the entangled interactions of the future energy technology portfolio and its operation within a coupled energy system. Amongst other energy demands CO2 emissions hydrogen production and future power plant capacities are presented. One main conclusion is that integrating the first elements of a large-scale hydrogen infrastructure into the German energy system already by 2030 is necessary for ensuring the supply of upscaling demands across all sectors. Within the regulatory regime of 2020 it seems that this decision may come too late which jeopardises the achievement of transition targets within the horizon 2050.

Covalent organic frameworks (COFs) are crystalline porous organic polymers built from covalent organic blocks that can be photochemically active when incorporating organic semiconducting units such as triazine rings or diacetylene bridges. The bandgap charge separation capacity porosity wettability and chemical stability of COFs can be tuned by properly choosing their constitutive building blocks by extension of conjugation by adjustment of the size and crystallinity of the pores and by synthetic post-functionalization. This review focuses on the recent uses of COFs as photoactive platforms for the hydrogen evolution reaction (HER) in which usually metal nanoparticles (NPs) or metallic compounds (generally Pt-based) act as co-catalysts. The most promising COF-based photocatalytic HER systems will be discussed and special emphasis will be placed on rationalizing their structure and light-harvesting properties in relation to their catalytic activity and stability under turnover conditions. Finally the aspects that need to be improved in the coming years will be discussed such as the degree of dispersibility in water the global photocatalytic efficiency and the robustness and stability of the hybrid systems putting emphasis on both the COF and the metal co-catalyst.

The use of hydrogen energy and the associated technologies is expected to increase in the coming years. The success of hydrogen energy technology (HET) is however dependent on public acceptance of the technology. Developing this new industry in a socially responsible way will require an understanding of the psychology factors that may facilitate or impede its public acceptance. This paper reviews 27 quantitative studies that have explored the relationship between psychological factors and HET acceptance. The findings from the review suggest that the perceived effects of the technology (i.e. the perceived benefits costs and risks) and the associated emotions are strong drivers of HET acceptance. This paper does though highlight some limitations with past research that make it difficult to make strong conclusions about the factors that influence HET acceptance. The review also reveals that few studies have investigated acceptance of different types of HET beyond a couple of applications. The paper ends with a discussion about directions for future research and highlights some practical implications for messaging and policy.

A new MgH₂–PrF₃–Al–Ni composite was prepared by ball milling under hydrogen atmosphere. After initial dehydrogenation and rehydrogenation Pr₃Al₁₁ MgF₂ PrH₃ and Mg₂NiH₄ nanoparticles formed accompanying the main phase MgH₂. The hydrogen absorption-desorption properties were measured by using a Sieverts-type apparatus. The results showed that the MgH₂–PrF₃–Al–Ni composite improved cycle stability and enhanced hydrogen desorption kinetics. The improvement of hydrogen absorption-desorption properties is ascribed to the synergetic effect of the in situ formed Pr₃Al11 MgF₂ PrH₃ and Mg₂NiH₄ nanoparticles. This work provides an important inspiration for the improvement of hydrogen storage properties in Mg-based materials.

The decarboxylation pathway in ethanol steam reforming ultimately favors higher selectivity to hydrogen over the decarbonylation mechanism. The addition of an optimized amount of Cs to Pt/m-ZrO2 catalysts increases the basicity and promotes the decarboxylation route converting ethanol to mainly H2 CO2 and CH4 at low temperature with virtually no decarbonylation being detected. This offers the potential to feed the product stream into a conventional methane steam reformer for the production of hydrogen with higher selectivity. DRIFTS and the temperature-programmed reaction of ethanol steam reforming as well as fixed bed catalyst testing revealed that the addition of just 2.9% Cs was able to stave off decarbonylation almost completely by attenuating the metallic function. This occurs with a decrease in ethanol conversion of just 16% relative to the undoped catalyst. In comparison with our previous work with Na this amount is—on an equivalent atomic basis—just 28% of the amount of Na that is required to achieve the same effect. Thus Cs is a much more efficient promoter than Na in facilitating decarboxylation.

This review describes recent research in the development of tank systems based on complex metal hydrides for thermolysis and hydrolysis. Commercial applications using complex metal hydrides are limited especially for thermolysis-based systems where so far only demonstration projects have been performed. Hydrolysis-based systems find their way in space naval military and defense applications due to their compatibility with proton exchange membrane (PEM) fuel cells. Tank design modeling and development for thermolysis and hydrolysis systems as well as commercial applications of hydrolysis systems are described in more detail in this review. For thermolysis mostly sodium aluminum hydride containing tanks were developed and only a few examples with nitrides ammonia borane and alane. For hydrolysis sodium borohydride was the preferred material whereas ammonia borane found less popularity. Recycling of the sodium borohydride spent fuel remains an important part for their commercial viability.

Hydrogen direct reduction has been proposed as a means to decarbonize primary steelmaking. Preferably the hydrogen necessary for this process is produced via water electrolysis. A downside to electrolysis is the large electricity demand. The electricity cost of water electrolysis may be reduced by using a hydrogen storage to exploit variations in electricity price i.e. producing more hydrogen when the electricity price is low and vice versa. In this paper we compare two kinds of hydrogen storages in the context of a hydrogen direct reduction process via simulations based on historic Swedish electricity prices: the storage of gaseous hydrogen in an underground lined rock cavern and the storage of hydrogen chemically bound in methanol. We find the methanol-based storages to be economically advantageous to lined rock caverns in several scenarios. The main advantages of methanol-based storage are the low investment cost of storage capacity and the possibility to decouple storage capacity from rate capacity. Nevertheless no storage option is found to be profitable for historic Swedish electricity prices. For the storages to be profitable electricity prices must be volatile with relatively frequent high peaks which has happened rarely in Sweden in recent years. However such scenarios may become more common with the expected increase of intermittent renewable power in the Swedish electricity system.

This review paper examines the possible pathways and possible technologies available that will help the shipping sector achieve the International Maritime Organization’s (IMO) deep decarbonization targets by 2050. There has been increased interest from important stakeholders regarding deep decarbonization evidenced by market surveys conducted by Shell and Deloitte. However deep decarbonization will require financial incentives and policies at an international and regional level given the maritime sector’s ~3% contribution to green house gas (GHG) emissions. The review paper based on research articles and grey literature discusses technoeconomic problems and/or benefits for technologies that will help the shipping sector achieve the IMO’s targets. The review presents a discussion on the recent literature regarding alternative fuels (nuclear hydrogen ammonia methanol) renewable energy sources (biofuels wind solar) the maturity of technologies (fuel cells internal combustion engines) as well as technical and operational strategies to reduce fuel consumption for new and existing ships (slow steaming cleaning and coating waste heat recovery hull and propeller design). The IMO’s 2050 targets will be achieved via radical technology shift together with the aid of social pressure financial incentives regulatory and legislative reforms at the local regional and international level.

The Reverse electrodialysis heat engine (REDHE) combines a reverse electrodialysis stack for power generation with a thermal regeneration unit to restore the concentration difference of the salt solutions. Current approaches for converting low-temperature waste heat to electricity with REDHE have not yielded conversion efficiencies and profits that would allow for the industrialization of the technology. This review explores the concept of Heat-to-Hydrogen with REDHEs and maps crucial developments toward industrialization. We discuss current advances in membrane development that are vital for the breakthrough of the RED Heat Engine. In addition the choice of salt is a crucial factor that has not received enough attention in the field. Based on ion properties relevant for both the transport through IEMs and the feasibility for regeneration we pinpoint the most promising salts for use in REDHE which we find to be KNO3 LiNO3 LiBr and LiCl. To further validate these results and compare the system performance with different salts there is a demand for a comprehensive thermodynamic model of the REDHE that considers all its units. Guided by such a model experimental studies can be designed to utilize the most favorable process conditions (e.g. salt solutions).

In this study hydrogen-storage glass microballoons were introduced into emulsion explosives to improve the detonation performance of the explosives. The effect of hydrogen-storage pressure on the detonation characteristics of emulsion explosives was systematically investigated. Detonation velocity experiments shows that the change of sensitizing gas and the increase of hydrogen pressure have different effects on the detonation velocity. The experimental parameters of underwater explosion increase first and then decreases with the increase of hydrogen pressure. The decrease of these parameters indicates that the strength of glass microballoons is the limiting factor to improve the detonation performance of hydrogen-storage emulsion explosives. Compared with the traditional emulsion explosives the maximum peak pressure of shock wave of hydrogen-storage emulsion explosives increases by 10.6% at 1.0 m and 10.2% at 1.2 m the maximum values of shock impulse increase by 5.7% at 1.0 m and 19.4% at 1.2 m. The stored hydrogen has dual effects of sensitizers and energetic additives which can improve the energy output of emulsion explosives.

The STOPIL-H2 project supported by the French Geodenergies research consortium aims to design a demonstrator for underground hydrogen storage in cavern EZ53 of the Etrez gas storage (France) operated by Storengy. Two types of tests are planned in this cavern: a tightness test with nitrogen and hydrogen then a cycling test during which the upper part of the cavern (approximately 200 m3) will be filled with hydrogen during 6 to 9 months. In this paper the PRA for the cycling test is presented comprising the identification of the major hazards and the proposed prevention and protection measures. The implemented methodology involves the following steps: data mining from the description of the project; analysis of lessons learned from accidents that occurred in underground gas storage and subface facilities; identification of the potential hazards pertaining to the storage process; analysis of external potential aggressors. Resulting as one of the outcomes of the PRA major accidental scenarios are presented and classified according to concerned storage operation phases as well as determined preventive or protective barriers able to prevent their occurrence of mitigate their consequences.

This work focuses on the experimental and numerical investigation of maximum overpressure and pressure dynamics during ignited hydrogen releases in a storage enclosure e.g. in marine vessel or rail carriage with limited vent size area i.e. the pressure peaking phenomenon (PPP) revealed theoretically at Ulster University in 2010. The CFD model previously validated against small scale experiments in a 1 m3 enclosure is employed here to simulate real-scale tests performed by the University of South-Eastern Norway (USN) in a chamber with a volume of 15 m3 . The numerical study compares two approaches on how to model the ignited hydrogen release conditions for under-expanded jets: (1) notional nozzle concept model with inflow boundary condition and (2) volumetric source model in the governing conservation equations. For the test with storage pressure of 11.78 MPa both approaches reproduce the experimental pressure dynamics and the pressure peak with a maximum 3% deviation. However the volumetric source approach reduces significantly the computational time by approximately 3 times (CFL = 0.75). The sensitivity analysis is performed to study the effect of CFL number the size of the volumetric source and number of iterations per time step. An approach based on the use of a larger size volumetric source and uniform coarser grid with a mesh size of a vent of square size is demonstrated to reduce the duration of simulations by a factor of 7.5 compared to the approach with inflow boundary at the notional nozzle exit. The volumetric source model demonstrates good engineering accuracy in predicting experimental pressure peaks with deviation from −14% to +11% for various release and ventilation scenarios as well as different volumetric source sizes. After validation against experiments the CFD model is employed to investigate the effect of cryogenic temperature in the storage on the overpressure dynamics in the enclosure. For a storage pressure equal to 11.78 MPa it is found that a decrease of storage temperature from 277 K to 100 K causes a twice larger pressure peak in the enclosure due to the pressure peaking phenomenon.

Recent development shows that carbon-based composites are proving to be the most promising materials in hydrogen energy production storage and conversion applications. In this study composites of the copper-based metal-organic framework with different ratios of graphite oxide have been prepared for hydrogen storage application. The developed materials are characterized by X-ray diffraction (XRD) gravimetric thermal analysis (TGA) scanning electron microscopy (SEM) and BET. The newly developed composites have an improved crystalline structure and an increased surface area. The results of the experiment showed that the composite material MOF/GO 20% can store 6.12% of hydrogen at −40 ◦C.

The extensive usage of fossil fuels has caused significant environmental pollution climate change and energy crises. The significant advantages of hydrogen such as cleanliness high efficiency and a wide range of sources make it quite promising. Hydrogen is prone to material damage which may lead to leakage. High-pressure leaking hydrogen is highly susceptible to spontaneous combustion due to its combustion characteristics which may cause jet fire or explosion accidents resulting in serious casualties and property damage. This paper presents a detailed review of the research progress on hydrogen leak diffusion characteristics leak spontaneous combustion mechanisms and material hydrogen damage mechanisms from the perspectives of theoretical analysis experiments and numerical simulations. This review points out that although a large number of research results have been obtained on the safety characteristics of hydrogen there are still some deficiencies and limitations. Further research topics are clarified such as further optimizing the kinetic mechanism of the high-pressure hydrogen leakage reaction and turbulence model exploring the expansion and dilution law of hydrogen clouds after liquid hydrogen flooding further studying the spontaneous combustion mechanism of leaked hydrogen and the interaction between mechanisms and investigating the synergistic damage effect of hydrogen and other components on materials. The leakage spontaneous combustion process in open space the development process of the bidirectional effect of hydrogen jet fuel and crack growth under the impact of high-pressure hydrogen jet fuel on the material may need to be explored next.

In recent years hydrogen is rapidly developing because it is environmentally friendly and sustainable. In this case hydrogen energy storage systems (HESSs) can be widely used in the distribution network. The application of hybrid electric-hydrogen energy storage systems can solve the adverse effects caused by renewable energy access to the distribution network. In order to ensure the rationality and effectiveness of energy storage systems (ESSs) configuration economic indicators of battery energy storage systems (BESSs) and hydrogen energy storage systems power loss and voltage fluctuation are chosen as the fitness function in this paper. Meanwhile multi-objective particle swarm optimization (MOPSO) is used to solve Pareto non-dominated set of energy storage systems’ optimal configuration scheme in which the technique for order preference by similarity to ideal solution (TOPSIS) based on information entropy weight (IEW) is used select the optimal solution in Pareto non-dominated solution set. Based on the extended IEEE-33 system and IEEE-69 system the rationality of energy storage systems configuration scheme under 20% and 35% renewable energy penetration rate is analyzed. The simulation results show that the power loss can be reduced by 7.9%–22.8% and the voltage fluctuation can be reduced by 40.0%–71% when the renewable energy penetration rate is 20% and 35% respectively in IEEE-33 and 69 nodes systems. Therefore it can be concluded that the locations and capacities of energy storage systems obtained by multi-objective particle swarm optimization can improve the distribution network stability and economy after accessing renewable generation.

In this review we provide a short overview of the Molecular Dynamics (MD) method and how it can be used to model the water splitting process in photoelectrochemical hydrogen production. We cover classical non-reactive and reactive MD techniques as well as multiscale extensions combining classical MD with quantum chemical and continuum methods. Selected examples of MD investigations of various aqueous semiconductor interfaces with a special focus on TiO₂ are discussed. Finally we identify gaps in the current state-of-the-art where further developments will be needed for better utilization of MD techniques in the field of water splitting.