The oscillatory baffled reactor (OBR) is one of the most promising reactor types for oxidative desulfurisation (ODS) due to high proven sulfur removal efficiency and improved mass and heat transport steps through the oxidation reaction. In Part III of this literature review, we review OBR design, scale-up, industrial application and economic considerations. Practical application of OBR for ODS process is described, catalytic systems are presented and the remaining challenges are outlined.

Catalyst layers, with commercial PtNi/TKK (TECNiE52; platinum 46.5 wt%), PtCo/TKK (TEC36E52; platinum 45.8 wt%) catalysts, and an in-house catalyst PtNi-NC (platinum 38.4 wt%), synthesised using acoustic mixer and a tube furnace, are prepared using three different ionomers: 20 wt% Nafion ® , 60 wt% polytetrafluoroethylene (PTFE), and an in-house 5 wt% ionomer (‘Ionomer X’). These inks are bar-coated onto carbon paper gas diffusion layers (GDLs), which are cut into 3 cm × 5 cm pieces. The coated layers are tested for oxygen reduction in a commercial gas diffusion electrode (GDE) test cell, FlexCell ® (Gaskatel GmbH, Germany), using 85 wt% phosphoric acid at both room temperature and at 155°C. This study evaluates the polynorbornene (PNB)-based in-house ionomer performance as binder and in-house catalyst oxygen reduction reaction (ORR) activity in comparison to commercial products. The catalyst layers are characterised using X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS), and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). Among the catalyst layers prepared with PTFE ionomer and tested at 155°C, the in-house catalyst demonstrates the highest ORR activity. Ionomer X proves to be a good candidate to be used as a per- and polyfluoroalkyl-free binder for high-temperature (HT) proton exchange membrane fuel cell (PEMFC) applications.

Industrial research and development (R&D) of advanced materials, particularly catalysts for sustainable technologies, is fundamentally hindered by a data analysis bottleneck. State-of-the-art characterisation instruments generate vast and complex datasets, the processing of which has become a significant impediment to the pace of innovation. This paper introduces the Johnson Matthey Data Science App Store, a strategic digital platform developed to overcome this challenge. The platform is a centralised, web-based suite of data science applications designed to democratise advanced analytics through intuitive, user-friendly graphical interfaces. The usefulness of the approach in generating value is illustrated with examples in three-dimensional device and micron level characterisation, particle size analysis and high-precision strain analysis.

Palladium(II) oxide/γ-alumina (PdO/γ-Al 2 O 3 ) catalysts are one of the most active catalytic components for the complete oxidation of methane. Under reaction conditions, especially in a wet feed, the catalysts suffer severe performance degradation. This study establishes a series of testing protocols to systematically investigate the causes of catalyst deactivation under methane oxidation reaction conditions. Four distinct catalyst deactivation modes are identified. Two of the deactivation modes are directly related to water, either from the feed gas or as a part of the reaction products, with one (Mode 2) being attributed to the formation of surface hydroxyl groups and the other (Mode 3) to the competitive adsorption of water on the catalysts. The impact of the two deactivation modes is acute and severe but reversible. In contrast, the other two deactivation modes are gradual and persistent but irreversible. Both modes are induced by methane oxidation reaction, with the impact of a wet feed (Mode 4) being substantially more severe than that of a dry feed (Mode 1). The major cause of the irreversible catalyst deactivation is attributed to surface reconstruction of palladium(II) oxide nanoparticles, which behaves as a passivation layer lowering the number of coordinately unsaturated palladium sites for methane activation. Although the passivation layer is relatively stable against thermal or hydrothermal treatment, it is not completely inert. Formation and partial regeneration of the passivation layer is a highly dynamic process and heavily depends on the reaction temperature: a lower reaction temperature (≤450°C) can lead to quicker catalyst deactivation; but a higher reaction temperature (between 500–550°C) can result in a greater extent of catalyst deactivation.

PFSA ionomer thin films were prepared from realistic ionomer solution concentrations at variable thicknesses on SiO2, Pt, and C. The thin films, prepared from two different ionomers, were then characterised using Neutron Reflectometry and Dynamic Vapour Sorption.  All ionomer films exhibited the expected increase in thickness due to hydration on exposure to a high relative humidity. Use of a custom-built environmental control chamber enabled measurement of the fast hydration equilibration times of the films, unlike previous studies that used salt solutions for humidity control. The data obtained enabled the probing of the effect of ionomer film thicknesses, substrate, and ionomer type. The measurements show that the different ionomers, despite taking up similar amounts of water per sulfonic acid group, showed significant differences in film swelling in response to that water uptake. The effect of ionomer type is shown to be greater than differences due to substrate. This study therefore provides mechanistic insight into the differences performance of the catalyst layers containing these ionomers at different ambient humidities beyond traditional characterisation techniques.

Pt-Au alloys have attracted attention as promising candidates for next-generation platinum channels due to their cost-effectiveness and enhanced performance on glass substrates. The addition of trace amounts of Zr is expected to improve chemical stability and tune key properties such as strength and conductivity. To examine the influence of Zr concentration, density functional theory was used to study the structural, thermal, and electronic properties of Pt-5Au-xZr alloys with Zr contents ranging from 0.0 to 5.0 wt%. The results show that Zr addition effectively improves the stability of Pt-5Au-xZr crystals. Regarding mechanical properties, the toughness of Pt-5Au-xZr alloys initially increases and then decreases with added Zr, while hardness exhibits an opposite trend. Notably, at 2.0 wt% Zr, the Pugh’s ratio peaks at 5.197 GPa and hardness reaches its lowest value of 2.215 GPa. Regarding high-temperature performance, Pt-5Au-2.0Zr exhibits excellent stability. At 1600 K, its thermal expansion coefficient is measured to be 3.60 × 10-5·K-1. DOS analysis confirms that Zr incorporation modifies the electronic states near the Fermi level: at moderate contents, electronic delocalization lowers the dislocation slip barrier, while excessive contents induce partial localization, strengthening rigidity but reducing ductility. Consequently, Pt-5Au-2.0Zr achieves an optimal balance of toughness and high-temperature stability. This study provides a comprehensive analysis of different Zr contents on the performance of Pt-5Au alloys, delivering important theoretical guidance for their potential engineering applications.

Currently, the traditional hydrodesulfurisation (HDS) process is extensively utilised in the oil refining industry to remove sulfur compounds from petroleum fractions which have environmental and health impacts in addition to affecting product quality. The HDS process needs high pressure and temperature, uses costly hydrogen gas and has low activity towards extraction of thiophene and its derivatives. Alternative desulfurisation processes like catalytic oxidative desulfurisation (ODS) are possible approaches because of mild process conditions, no need for hydrogen and efficiency in removing thiophene and its derivatives. ODS is developed using various types of catalyst, oxidants and designs of reactors under different operating conditions. In continuation with developing more workable and economical parameters in ODS technology, different types of reactors are considered as alternatives to the traditional batch reactors. This three-part work investigates the most recent developments in reactors for ODS processes and reviews the advantages, limitations and future potential of each reactor.

In power grid modernisation, optimal network use is essential to preserving acceptable voltage profiles, boosting voltage stability, reducing power losses, and strengthening system security and dependability. This can be accomplished by strategically placing reactive power compensation devices within transmission and distribution networks, such as capacitor banks, synchronous condensers, flexible alternating current transmission system (FACTS) devices and custom power devices. The optimal location and size of these devices are essential for effective investment, but previous research has mostly concentrated on a variety of methods for this goal, using different indices to evaluate power loss, voltage stability, voltage profile and line loadability. Despite these initiatives, there is still a lack of a thorough analysis of how current indices and methodologies are applied to all varieties of reactive power compensation devices. This paper offers a detailed literature review on the ideal placement and sizing of these devices, encompassing analytical, conventional and hybrid-based techniques. It discusses key objectives such as power loss reduction, voltage deviation (VD) mitigation, voltage stability enhancement and improvements in system reliability and security. Additionally, the paper examines the relevance of reactive power for stakeholders, including transmission system operators (TSOs), distribution system operators (DSOs) and power generating companies, and explores the mathematical modelling of optimal reactive power dispatch (ORPD), considering the impact of renewable energy sources (RESs) and the role of FACTS devices.

Johnson Matthey’s international journal of research exploring science and technology in industrial applications Contents Volume 69, Issue 2, April 2025 156 Guest Editorial: Opportunities for Innovation in the Circular Economy By Jeanette Simpson 158 Review of Recovery and Purification Processes of Rare Earth Elements from Nickel-Metal Hydride Spent Batteries By Widya Aryani M, Azwar Manaf, Erik Prasetyo et al. 170 Autonomous Structural Health Monitoring and Remaining Useful Life Estimation of Floating Offshore Wind Turbine Cables: Part I By Metehan Berker, Perin Ünal, Bilgin U. Deveci et al. 187 Autonomous Structural Health Monitoring and Remaining Useful Life Estimation of Floating Offshore Wind Turbine Cables: Part II By Metehan Berker, Perin Ünal, Bilgin U. Deveci et al. 198 Severe Plastic Deformation Methods Influence on the Structure and Properties of Metal Materials: A Review By A. V. Volokitin, I. E. Volokitina, A. I. Denissova and M. Seref Sonmez 214 Effectiveness Evaluation of Pyrometallurgy and Hyrometallurgy Methods in the Recycling Process of Neodymium-Iron-Boron Permanent Magnet and Rare Earth Metals Recovery: A Review By Lucky Darmawan, Azwar Manaf, Erik Prasetyo et al. 233 The Development of Rare Earth Based Permanent Magnets and Its Relation to the Circular Economy By Lucky Darmawan, Azwar Manaf, Erik Prasetyo et al. 247 Exploration of Single Atom Alloy Catalysis for Industrial Applications: Part I By Geofrey Njovu and Liliana Lukashuk 260 Exploration of Single Atom Alloy Catalysis for Industrial Applications: Part II By Geofrey Njovu and Liliana Lukashuk 271 Choosing an Analogue to Digital Converter with Data Safety in Mind By C. R. Tipton 283 Structural-Phase State of Austenitic 20GL Steel after Thermal Treatment by Normalising and High-Temperature Tempering By Alyona Russakova, Almira Zhilkashinova, Madi Abilev et al. 299 Three-Dimensional Oldroyd-B Fluid Flow Past a Stretching Surface with Magnetic Field, Nanofluid Particles and Cattaneo-Christov Double Diffusion Effects By G. Murali, J. Venkata Madhu, G. Deepa et al. 321 “Introduction to Particle Technology” Reviewed by Alex Munnoch 327 Johnson Matthey Highlights

This study aims to coat Ti6Al4V alloy with Ti-xHA (x = 2.5−10 wt%) mixture to improve its surface properties. A new approach using a powder metallurgical pressure-assisted sintering method was applied to the coating process. The in situ sintering and coating process was performed at 950°C for 45 min in a vacuum atmosphere of 10–4 mbar. A pressure of 50 MPa was applied during the sintering process. Staphylococcus aureus (ATCC® 29213TM) and Escherichia coli (ATCC® 25922TM) cultures were used to determine the antibacterial activity of the sintered and coated samples. The electrochemical properties of the samples were studied by Tafel extrapolation and potentiodynamic polarisation tests. The results showed that the coating layer containing 7.5 wt% of hydroxyapatite (HA) increased the antibacterial property against gram-positive and gram-negative bacterial cultures. Furthermore, it was determined that the icorr value of the material decreased and the corrosion resistance improved with an increasing HA ratio. In addition, no active-passive oxidation zone formation was observed up to 2000 mV in the HA-added samples.