Johnson Matthey Technology Review: Most Recent Articles

Mon, 01 Apr 2024 00:00:00 GMT

Guest Editorial

Professor ATHANASIOS TSOLAKIS — Mon, 01 Apr 2024 00:00:00 GMT

Hydrogen Spillover Mechanisms on Copper on Zinc Oxide-Based Catalysts for Carbon Dioxide Hydrogenation to Methanol

Mustafa Al Salmi — Mon, 01 Apr 2024 00:00:00 GMT

The Effect of Platinum Single Atoms in Titania for Photocatalytic Applications

C. A. G. Bezerra, D. Mamedov and N. Alonso-Vante — Mon, 01 Apr 2024 00:00:00 GMT

The photocatalytic effect of titania has long been studied with respect to water oxidation and hydrogen evolution. At present, the modification of this semiconducting material by platinum single atoms (Pt-SAs) represents an interesting approach that has been developed in the past decade and has given good results in the photocatalytic hydrogen evolution reaction (HER). Experimental studies have shown that the deposition of Pt-SAs on the titania surface, in aqueous systems, is a spontaneous process and can also be promoted by different reducing processes. Theoretical studies suggest that this deposition is a site-specific reaction, which occurs in oxygen vacancies on the titania surface. Under such conditions, the Pt-SAs are not in a metallic state, due to the interaction with neighbouring atoms of the substrate. This complex system can be probed using different advanced characterisation techniques, which provide a deeper understanding about the modified surface and how this modification improves the photocatalytic performance of titania.

“Combustion Chemistry and the Carbon Neutral Future”

Reviewed by Ceren Aydın and Howard Hess — Mon, 01 Apr 2024 00:00:00 GMT

Mechanochemistry: A Green and Fast Method to Prepare a New Generation of Metal Supported Catalysts

Mon, 01 Apr 2024 00:00:00 GMT

In this review, we report on recent advances in the use of mechanochemistry to synthesise new catalytic materials. We report recent results obtained by our groups where a rational design of the milling parameters led to the synthesis of advanced materials with novel properties such as unconventional arrangements of metals on the surface of oxide support materials, highly dispersed metals or the stabilisation of species in particular oxidation states. These properties resulted in superior catalytic performances of the mechanochemically-synthesised catalysts compared to their counterparts prepared by traditional impregnation methods. To illustrate these advances, we review the progress made in two important fields of catalysis where noble metals are used: (i) emission control catalysis using palladium-based materials; (ii) the development of photocatalysts to produce hydrogen based on gold and palladium materials.

A Review of the Sources, Environmental Behaviours and Human Health of Atmospheric Microplastics

Bowen Zhang, Rencheng Zhu and Yunjing Wang — Mon, 01 Apr 2024 00:00:00 GMT

The article places emphasis on the latest advancements in this field, particularly focusing on indoor and outdoor microplastic (MP) pollution, including their emission, behaviour and potential health hazards. Gaining an in-depth understanding of these factors is crucial for devising effective strategies to mitigate the impact of microplastics (MPs) on human health and the environment. Indoor MP abundance is generally higher than outdoor levels, with textiles serving as a primary source of indoor airborne MPs. Traffic-derived MP particles, MP fibres in residential areas, agricultural plastic mulch, marine MPs and landfill sites appear to be contributors to outdoor atmospheric MP pollution. Factors such as wind direction, wind speed, precipitation and snowfall, along with the physical characteristics and secondary suspension of MPs, collectively influence their behaviour, distribution and fate. Inhalation and ingestion constitute the main exposure pathways for airborne MPs, potentially leading to health issues like respiratory inflammation. Therefore, gaining a deeper insight into the behaviour and impact mechanisms of atmospheric MPs aids in formulating effective risk management strategies to safeguard human health and maintain environmental sustainability.

Fabrication of Two-Dimensional Material Membranes

Haowen Li, Qingqing Pan, Xiao Sui and Yuan Chen — Mon, 01 Apr 2024 00:00:00 GMT

Membrane separation is an energy-efficient separation process. Two-dimensional (2D) materials have shown potential as a new generation of membrane materials due to their unique structures and physicochemical properties. The separation performance of 2D material membranes crucially depends on how 2D nanosheets are assembled in membranes, such as interlayer spacing between stacked nanosheets, chemical properties of nanosheet surfaces, alignment of nanosheets and thickness of membranes, which are closely related to their fabrication methods. This short review concisely overviews commonly used membrane fabrication methods for different types of 2D materials, including graphene-based materials, 2D covalent organic frameworks, 2D metal-organic frameworks, MXenes and other 2D materials. The representative 2D material membranes resulting from their essential fabrication methods are discussed. The advantages and shortcomings of different fabrication methods are compared. The critical challenges to realising large-scale production of 2D material membranes for practical applications are highlighted.

Extension of a Zero-Dimensional Mixing-Controlled Combustion Model for the Development of a NOx–Free System Based on the Oxy-Combustion Concept

José R. Serrano, J. Javier López, Jaime Martín and Gabriela Bracho — Mon, 01 Apr 2024 00:00:00 GMT

Oxy-combustion is a promising concept to achieve an extremely clean combustion, independently of the fuel type, because, on the one hand, it is a NOx-free combustion and, on the other hand, the CO2 produced during combustion can be easily captured once the water vapour is removed from the exhaust gases stream, consequently allowing also carbon neutral operation. An existing zero-dimensional (0D), mixing-controlled combustion model, developed for a standard diesel combustion scenario, has been adapted to the oxy-fuel combustion scenario. Initially, the model over-predicted the heat release at the end of the combustion process. The main model adaptation was to modify the relationship between the average YO2 and the effective YO2 (i.e. the one of the charge actually entrained by the spray), to be consistent with the significant increase in compression ratio needed in the oxy-fuel context. As a result, a model able to correctly predict the combustion behaviour at any operating condition has been obtained, which finally represents a very suitable tool to assist in the concept development.

“Characterization of Minerals, Metals, and Materials 2023”

Reviewed by Gareth Hatton — Mon, 01 Apr 2024 00:00:00 GMT

Johnson Matthey Highlights

Mon, 01 Apr 2024 00:00:00 GMT

Advancements in Green Ammonia Production and Utilisation Technologies

John Humphreys and Shanwen Tao — Mon, 01 Apr 2024 00:00:00 GMT

Green ammonia, produced through renewable energy-powered electrochemical and thermal processes, is emerging as a promising candidate to replace fossil fuel-based ammonia in the fertiliser, transportation and energy sectors. This paper provides an overview of the production methods, utilisation methods and technological advancements for green ammonia. The electrochemical production and Haber-Bosch with renewable hydrogen and energy are discussed in detail highlighting recent material advances. Green ammonia utilisation methods are discussed with direct use cases such as ammonia combustion and direct ammonia fuel cells examined. Green ammonia’s potential as a carbon-free hydrogen carrier is also discussed in regards to ammonia cracking for effective hydrogen recovery. This paper concludes that green ammonia has the potential to play a significant role in the transition to a sustainable energy system and offers new opportunities for the fertiliser, transportation and energy industries.

Potential of Hydrogen Internal Combustion Engine for the Decarbonised Passenger Vehicle

By Seung Woo Lee, Hong-kil Baek and Kyeonghyeon Lee — Mon, 01 Apr 2024 00:00:00 GMT

CO2 regulations are becoming very stringent due to the goal of reducing greenhouse gases and achieving carbon neutrality. It has already become a common situation that electric vehicles are emerging as eco-friendly power systems rather than vehicles equipped with conventional internal combustion engines and their share in the market is increasing. However, even with an internal combustion engine, CO2 can be drastically reduced if a carbon-free fuel such as hydrogen is used. Raw nitrogen oxides (NOx) emissions can be overcome to a certain level through ultra-lean burn operation, but in order to balance the amount of hydrogen and air in the limited space of the combustion chamber, a drop in the engine’s maximum output should be accepted. Hyundai Motor Company (HMC) also previously developed an engine using hydrogen fuel (1), but was unable to progress to mass production. Since then, hybrid technology has become popular, and with the development of hydrogen injection devices, an era has arrived where mass production becomes a possibility. For this reason, studies on internal combustion engines using hydrogen fuel based on existing spark ignition or compression ignition engines are rapidly increasing. In this study, a hydrogen fuel engine was designed and manufactured based on the mass produced gasoline spark ignition engine. CO2 level was confirmed from initial performance evaluation, and it was found that raw NOx levels and maximum power were in a trade-off relationship with each other under the same air-charging system application. In addition, the method to improve maximum engine torque was verified while maintaining the raw NOx level, and the maximum engine power improvement level was confirmed when raw NOx emissions were allowed to increase. Thereby the potential of the carbon-neutral internal combustion engine has been demonstrated.

Editorial: 10th Anniversary of Johnson Matthey Technology Review

SARA COLES Editor — Mon, 01 Jan 2024 00:00:00 GMT

Effect of Ruthenium Targets on the Growth and Electrical Properties of Sputtering Ruthenium Films

Yue Shen, Yanting Xu, Jun Gan, Renyao Zhang and Ming Wen — Mon, 01 Jan 2024 00:00:00 GMT

Ruthenium targets were prepared by vacuum hot pressing of ruthenium powder with different morphologies. Ruthenium films were then deposited on a SiO2/Si(100) substrate for different times by radio frequency (RF) magnetron sputtering. The relationship in terms of the microstructure and electrical properties between the ruthenium targets and resultant films at different conditions were studied by means of field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), atomic force microscopy (AFM) and four-point probe. The results showed that parameters such as the average deposition rate, surface roughness, crystallisation properties and growth rate were directly related to the homogeneity of the microstructure of the ruthenium targets, but there was no correlation between the crystal orientations of the films and the targets. Moreover, the resistivity of ruthenium films was positively correlated with that of the ruthenium targets.

Knowledge Structure of New Energy Vehicle Policy Research

Ruqia Shaikh, Asim Qazi, Xiaoli Wang and Diby Francois Kassi — Mon, 01 Jan 2024 00:00:00 GMT

Globally, transport is responsible for 23% of energy-related carbon dioxide emissions and 80% of these emissions are attributable to road transport. Significant transformations, including extensive electrification of the sector, are necessary to achieve climate change goals. To understand new energy vehicle (NEV) policy research, we explore the status, knowledge base and research frontiers of NEV policy research by studying 355 papers collected from the Web of Science™ (WoS) Core Collection database. We map NEV policy research trends and knowledge structure development using knowledge domain technology and bibliometric techniques. The knowledge base analysis shows that: (a) NEV policy formation and evaluation; (b) policy incentives and consumer adoption; and (c) consumer preferences towards NEV adoption are all essential knowledge foundations in NEV policy research and development (R&D). The efficiency of NEV policy, cost-effectiveness of alternative fuel vehicles (AFVs), consumer preferences for NEV adoption, hydrogen energy and fuel cell vehicles, climate policy and CO2 emissions are five main lines of research in NEV policy studies. With the highest number of publications from Tsinghua University, China is the most active country in NEV policy research. Energy Policy, Sustainability and Journal of Cleaner Production are the core journals and Energy and Fuels and Environmental Sciences are the core disciplines of NEV policy research. The findings of this analysis help policymakers and researchers to navigate the literature on NEV, provide a clear map of existing works, identify the gaps and recommend promising avenues for future studies.

Non-Linear Thermophysical Behaviour of Transition Metal Titanium

Mon, 01 Jan 2024 00:00:00 GMT

The propagation of ultrasonic waves in the hexagonal closed packed (hcp) structured lanthanide metal titanium has been investigated in the temperature range 300–1000 K. For this, initially the higher-order elastic constants (second-order elastic constants (SOECs) and third-order elastic constants (TOECs)) were computed using the Lennard-Jones interaction potential model. With the help of SOECs, other elastic moduli such as Young’s modulus (Y), bulk modulus (B), shear modulus (G), Poisson’s ratio (σ) and Pugh’s ratio (B/G) were computed using the Voigt-Reuss-Hill approximation. Three types of orientation-dependent ultrasonic velocities, including Debye average velocities, were evaluated using the calculated SOECs and density of titanium in the same temperature range. Thermophysical properties such as lattice thermal conductivity, thermal relaxation time, thermal energy density, specific heat at constant volume and acoustic coupling constant were evaluated under the same physical conditions. The ultrasonic attenuation due to phonon-phonon interaction is most significant under the chosen physical conditions. The ultrasonic properties of titanium are correlated with thermophysical properties to understand the microstructural features and nature of the material.

Influence of Temperature and Orientation on Elastic, Mechanical, Thermophysical and Ultrasonic Properties of Platinum Group Metal Carbides

Anurag Singh and Devraj Singh — Mon, 01 Jan 2024 00:00:00 GMT

The elastic, mechanical, thermophysical and ultrasonic properties of platinum group metal (pgm) carbides XC (X = rhodium, palladium, iridium) have been investigated at room temperature. The Coulomb and Born-Mayer potential model was used to compute second- and third-order elastic constants (SOECs and TOECs) at 0 K and 300 K. The obtained values of SOECs were used to evaluate mechanical properties such as Young’s modulus, bulk modulus, shear modulus, Pugh’s indicator, Zener anisotropic constant and Poisson’s ratio at room temperature. The materials show brittle nature as the value of Pugh’s indicator for pgm carbides is ≤1.75. The values of SOECs were used to compute the ultrasonic velocities along <100>, <110> and <111> directions for the longitudinal and shear modes of wave propagation. Further, the values of Debye temperature, thermal conductivity, specific heat per unit volume, energy density, average value of ultrasonic Grüneisen parameter, thermal relaxation time and non-linear parameter were calculated with the help of SOECs, TOECs, ultrasonic velocities, density and molecular weight. Finally, the ultrasonic attenuation due to phonon-phonon interaction and due to thermoelastic relaxation mechanisms were calculated with the use of all associated parameters. The calculated values of elastic, mechanical, thermophysical and ultrasonic properties are compared with available literature and discussed.

Long-term Evaluation of Culturable Fungi in a Natural Aging Biofilm on Galvanised Steel Surface

Duygu Göksay Kadaifciler, Tuba Unsal and Esra Ilhan-Sungur — Mon, 01 Jan 2024 00:00:00 GMT

Fungi commonly found in municipal water can participate in natural biofilm formation on the surface of galvanised steel despite the toxic effect of zinc. Depending on the age of the biofilm, fungal diversity may vary. To examine this hypothesis, natural biofilm formation was allowed on galvanised steel surfaces over six months in a model recirculating water system. Fungal colonies with different morphologies were obtained monthly from biofilm and water samples and then identified by both morphological and molecular approaches. In addition, the biofilm layer was examined by electrochemical impedance spectroscopy (EIS) analysis and scanning electron microscopy (SEM). It was determined that fungi were included in the naturally aging biofilm formed on galvanised steel surfaces during the experiment. The diversity and the number of fungi in the biofilm and water changed over the experiment. All fungi isolated from the biofilm and water were found to be members of the Ascomycota phylum. F. oxysporum was the first fungus to be involved in the biofilm formation process and was one of the main inhabitants of the biofilm together with Penicillium spp. In addition, EIS data showed that the structure of the biofilm changed as it aged. The results of this study may lead to a better understanding of naturally aging biofilms involving fungi in municipal water systems, as well as the development of new strategies for effective disinfection of fungi based on biofilm age.

Porous Metallic Implants from Additive Manufacturing to Biocorrosion: A Review

Salwa El Baakili, Patrick Munyensanga, Meriame Bricha and Khalil El Mabrouk — Mon, 01 Jan 2024 00:00:00 GMT

The improved bulk and surface function of manufactured implants has advanced implantation procedures, leading to a decline in surgical risks. Many current techniques discussed in the literature are related to additive manufacturing (AM) of lightweight implants based on reliable, precise, flexible scaffolds and capable of mimicking bone properties while incorporating other useful features. These techniques have evolved for the production of a variety of biocompatible materials. AM has progressed beyond prototype to full-scale manufacturing of metals, polymers and ceramic products. However, metallic implants often fail in vivo due to biocorrosion and deterioration, limiting implant longevity. This study reviews current trends and approaches to enhancing the surface corrosion resistance of porous metallic implants and the effect of interfacial films on biological activity. The art of porous metallic implants manufactured by AM and their biocorrosion behaviour are discussed. This review also evaluates future trends and perspectives in additively manufactured synthetic orthopaedic implants porous with enhanced surface morphology.

Rhodium and Rhodium-Alloy Films and Nanoparticles: Part I

Yicheng Zhou, Wangping Wu, Qinqin Wang and Liangbing Wang — Mon, 01 Jan 2024 00:00:00 GMT

Noble metals are key to various research fields and noble metal nanomaterials are directly relevant to optics, catalysis, medicine, sensing and many other applications. Rhodium-based nanomaterials have been less studied than metals such as gold, silver or platinum. There have been many improvements in characterisation tools over the years and knowledge about rhodium chemistry and nanomaterials is growing rapidly. Rhodium nanoparticles are widely used as catalysts for automotive emissions control and for hydrogen and oxygen precipitation reactions in electrolytic cells. Novel applications in electronics, anticancer drugs and aerospace are being revisited. In Part I of this two-part review, we cover different strategies for the synthesis of rhodium films and nanoparticles.

Rhodium and Rhodium-Alloy Films and Nanoparticles: Part II

Yicheng Zhou, Wangping Wu, Qinqin Wang and Liangbing Wang — Mon, 01 Jan 2024 00:00:00 GMT

Part I of this review covered the synthesis methods for synthesis of rhodium films and nanoparticles (1). In Part II, we review the literature on the current and potential applications of rhodium and rhodium alloy films and nanoparticles in catalysis, components for the glass, chemical and electronic industries, thermal sensors and anticancer drugs.

“Hydrogen Technologies”

Reviewed by Gareth Hart and Andy Walker — Mon, 01 Jan 2024 00:00:00 GMT

The Discovery of the Isotopes of the Platinum Group of Elements: Update 2024

John W. Arblaster — Mon, 01 Jan 2024 00:00:00 GMT

Johnson Matthey Highlights

Mon, 01 Jan 2024 00:00:00 GMT

Johnson Matthey Technology Review: Most Recent Articles

Contents

Guest Editorial

Hydrogen Spillover Mechanisms on Copper on Zinc Oxide-Based Catalysts for Carbon Dioxide Hydrogenation to Methanol

The Effect of Platinum Single Atoms in Titania for Photocatalytic Applications

“Combustion Chemistry and the Carbon Neutral Future”

Mechanochemistry: A Green and Fast Method to Prepare a New Generation of Metal Supported Catalysts

A Review of the Sources, Environmental Behaviours and Human Health of Atmospheric Microplastics

Fabrication of Two-Dimensional Material Membranes

Extension of a Zero-Dimensional Mixing-Controlled Combustion Model for the Development of a NOx–Free System Based on the Oxy-Combustion Concept

“Characterization of Minerals, Metals, and Materials 2023”

Johnson Matthey Highlights

Advancements in Green Ammonia Production and Utilisation Technologies

Potential of Hydrogen Internal Combustion Engine for the Decarbonised Passenger Vehicle

Editorial: 10th Anniversary of Johnson Matthey Technology Review

Effect of Ruthenium Targets on the Growth and Electrical Properties of Sputtering Ruthenium Films

Knowledge Structure of New Energy Vehicle Policy Research

Non-Linear Thermophysical Behaviour of Transition Metal Titanium

Influence of Temperature and Orientation on Elastic, Mechanical, Thermophysical and Ultrasonic Properties of Platinum Group Metal Carbides

Long-term Evaluation of Culturable Fungi in a Natural Aging Biofilm on Galvanised Steel Surface

Porous Metallic Implants from Additive Manufacturing to Biocorrosion: A Review

Rhodium and Rhodium-Alloy Films and Nanoparticles: Part I

Rhodium and Rhodium-Alloy Films and Nanoparticles: Part II

“Hydrogen Technologies”

The Discovery of the Isotopes of the Platinum Group of Elements: Update 2024

Johnson Matthey Highlights