Latest Content

Theoretical Study on Copper Adsorption on ZnO Surfaces

Tue, 23 Apr 2024 00:00:00 GMT

ABSTRACT: The study of Cu on ZnO surfaces is a topic of ongoing research due to the importance of Cu as a promoter in the low-temperature synthesis of methanol, the water-gas shift process, and methanol steam reforming. The role of ZnO in support-ing the stabilization of the Cu atoms and promoting the CO2 hydrogenation reaction is multifaceted and involves a range of physical and chemical factors. In this work, we used density functional theory (DFT) calculations to investigate the Cu adsorp-tion on ZnO surfaces on different sites. Bader charge analysis, adsorption energy, and phonon inelastic neutron scattering (INS) associated with most stable systems were calculated and compared with previous theoretical and experimental results. We found that atomic Cu adsorption on hollow site of ZnO(111) is the most stable site and most favorable site for Cu adsorption compar-ing to other ZnO surfaces. This is due to the strong metal-oxygen interaction between Cu and the ZnO surface. We concluded that further studies are needed to investigate the catalytic activity of this catalyst under realistic reaction conditions with realistic models of Cu supported on ZnO.

Effect of Hf on the Microstructure and Mechanical Property of Pt-15Ir-xHf-0.5Y Alloy

Tue, 23 Apr 2024 00:00:00 GMT

The influence of Hf content on the recrystallization and aging behavior of hot-rolled Pt-15Ir-xHf-0.5Y alloy was investigated by SEM, EBSD and hardness tests. The results show that the alloy texture evolves from a multi-peak one biased towards rolling direction-transverse direction (RD-TD) in the hot rolling state to a multi-peak one symmetrical along the normal direction (ND) after recrystallization annealing. The fibrous grains become equiaxial after recrystallization annealing, increase of Hf content refines the grains. Pt-15Ir-xHf-0.5Y alloy exhibits age-hardening behavior at the temperature range of 600°C~900°C, which is due to the precipitation of (Pt, Ir)5Y phase. Increasing Hf addition effectively improves the hardness through promoting the precipitated amount of (Pt, Ir)5Y phase. However, the internal oxidation within grain boundaries is deteriorated with the high-content Hf addition. The results of this study provide an insight into tailoring the microstructures and mechanical properties of the Pt-Ir high-temperature alloys.

A New Approach to Ti-HA Bio Composite: Pressure-Assisted Coating on the Antibacterial and Electrochemical Properties of Ti6Al4V

Tue, 23 Apr 2024 00:00:00 GMT

This study aims to coat Ti6Al4V alloy with Ti-xHA (x=2.5-10wt.%) 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 50MPa was applied during the sintering process. Staphylococcus aureus (ATCC 29213) and Escherichia coli (ATCC 25922) 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 polarization tests. The results showed that the coating layer containing wt.%7.5 of 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.

A Comprehensive Exploration of Biomass Gasification Technologies Advancing United Nations Sustainable Development Goals

Thu, 11 Apr 2024 00:00:00 GMT

Abstract: The pursuit of sustainable energy sources on a worldwide scale is a crucial and pressing matter, with the United Nations Sustainable Development Goals (UNSDGs) offering a comprehensive framework for properly addressing this challenge. This paper provides an overview of the various technologies now available for the process of biomass gasification. Compared to other renewable energy sources, which have undergone significant technological advancements in recent years, the field of biomass conversion is still relatively new. Keeping up with the newest breakthroughs becomes increasingly crucial as new conversion techniques are rapidly being created. Keeping up with the latest advancements and potential enhancements in biofuel conversion technology is essential due to their rapid development. In the thermochemical conversion process called "biomass gasification," biomass solid source materials are degraded or incompletely burned in an oxygen-free or oxygen-deficient high-temperature atmosphere, resulting in the production of biomass gas. Biomass gas can be utilized in industry to directly power industrial boilers for steam production, as well as for cooking or heating purposes in rural areas. The purified biomass gas can be utilized to operate a generator set, so facilitating the provision of electricity to areas lacking access to it. The utilization of biomass gasification technology alters the traditional approach of directly igniting biomass to generate power. Gasification technology converts biomass into a clean and combustible gas, significantly improving the efficiency of using biomass energy. This essay will largely concentrate on the methodologies and protocols employed in biomass gasification. The article provides an overview of various gasification procedures and the potential applications of the resulting products. It delves into different biomass gasification techniques, including upstream, gasification, and downstream processes, highlighting their importance in transforming biomass into clean and combustible gases. The review focuses on methodologies and protocols employed in biomass gasification, recognizing its pivotal role in sustainable energy generation. Additionally, the article discusses the challenges associated with gasification technology, such as tar formation, biomass heterogeneity, and uneven biomass supply in different seasons. It emphasizes the need for further research and infrastructure development to overcome these barriers and facilitate the efficient distribution and commercialization of biomass gasification technology. Overall, the scope of the article extends to providing insights into the status, challenges, and future prospects of biomass gasification for achieving sustainable energy goals.

Autonomous Structural Health Monitoring and Remaining Useful Life Estimation of Floating Offshore Wind Turbine Cables

Mon, 08 Apr 2024 00:00:00 GMT

Abstract— Floating offshore wind (FOW) farms are key in meeting Europe’s renewable energy targets, harnessing wind energy from waters 60m or deeper, where bottom-fixed farms are unfeasible. Additionally, floating structures allow for the installation of larger turbines than stationary farms, which in turn leads to a greater energy output. However, cable failures dramatically impact the energy transmission from the farms and cause most of the financial losses. Monitoring and maintenance tasks are challenging due to the harsh ocean conditions. The FLOW-CAM project, supported by European Union’s HORIZON 2020 program, studies the structural health monitoring (SHM) of defects in the power cables of the FOW farms which encompass inspection and detection applications. An SHM system integrated with a remotely operated vehicle (ROV) was developed for underwater inspection and maintenance, supporting collection and presentation of essential data through an advanced interface. Image data from underwater systems are analyzed using computer vision techniques. Investigations into cable defect detection and the estimation of corrosion and remaining useful life have been held to monitor cable health, achieving results close to reality. FLOW-CAM’s collective works establish a basis for advancing underwater inspection and maintenance, concentrating on the development of practical and effective tools and strategies to optimize the functionality and reliability of FOW farms.

The Effect of Platinum Single Atoms in Titania for Photocatalytic Applications

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”

Mon, 01 Apr 2024 00:00:00 GMT

“Characterization of Minerals, Metals, and Materials 2023”

Mon, 01 Apr 2024 00:00:00 GMT

Guest Editorial

Mon, 01 Apr 2024 00:00:00 GMT

Johnson Matthey Highlights

Mon, 01 Apr 2024 00:00:00 GMT

Active Sites of Cu/ZnO-Based Catalysts for CO2 Hydrogenation to Methanol

Thu, 14 Mar 2024 00:00:00 GMT

Heterogeneous Cu/ZnO-based catalysts are widely used for CO₂ hydrogenation to methanol, but limitations remain for industrial applications. These include achieving high methanol selectivity and conversion, and mitigating deactivation by water poisoning. This review explores the role of active sites on Cu/ZnO-based catalysts in CO₂ conversion. The synergistic interaction between Cu and ZnO is emphasized, particularly regarding interfacial effects on CO activation and formate formation. The discussion covers theoretical and experimental perspectives on active site characteristics, including defects, vacancies, steps, and strain. Additionally, the review explores the connection between Cu/ZnO-based catalysts properties and methanol synthesis activity. It examines how preparation methods influence catalyst performance and the impact of doping with elements like CeO₂, Al₂O₃, and ZrO₂ on CO₂ conversion selectivity. We conclude that ZnO enhances Cu dispersion and promotes a synergistic effect at the interface, leading to improved catalytic performance.

Ultrafast spectroscopy at the Central Laser Facility

Thu, 29 Feb 2024 00:00:00 GMT

In this article, we will examine ultrafast spectroscopy techniques and applications, covering ‘time-resolved IR’ (TR-IR) spectroscopy, time resolved visible (TA) spectroscopy, two-dimensional IR (2D-IR) spectroscopy, Kerr-gated Raman spectroscopy, time-resolved Raman and surface sum-frequency generation (SSFG) spectroscopy. In addition to introducing each technique, we will cover some basics, such as what kinds of lasers are used and discuss how these techniques are applied to study a diversity of chemical problems such as photo-catalysis, photo-chemistry, electro-catalysis, battery electrode characterisation, zeolite characterisation and protein structural dynamics.

Oxidation Kinetics of FeCr and FeCrAl Alloys: Influence of Secondary Processes

Thu, 29 Feb 2024 00:00:00 GMT

The paper presents a mathematical model for describing of thermogravimetric curves of growth of scale with its simultaneous sublimation during oxidation of the surface of a metal or alloy. For alloys FeCr and FeCrAl, a decrease in the effective reaction area as a result of the formation of the oxide of the alloying element - lanthanum or yttrium (together with the formation of the main oxide - Cr2O3 or Al2O3) is considered. For metals, the case of increasing this area is also considered. During the oxidation of the chromia-forming alloy, another secondary process is added - the evaporation of Cr2O3. Therefore, the equations describing the kinetics of changes in mass of these alloys are different. Equations are also considered that make it possible to describe the kinetics of the oxidation process taking into account the initial non-isothermal heating. The formal equations of the oxidation process with an increase in the reaction surface as a result of crushing metal powder are also considered. The resulting equations are used to describe the kinetic curves of changes in the mass of the samples under study. The given equations can be considered as a more accurate approximation to describe the experimental data than the formulas known so far.

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

Wed, 17 Jan 2024 00:00:00 GMT

“Hydrogen Technologies”

Mon, 08 Jan 2024 00:00:00 GMT

Johnson Matthey Highlights

Thu, 21 Dec 2023 00:00:00 GMT

Editorial: 10th Anniversary of Johnson Matthey Technology Review

Fri, 08 Dec 2023 00:00:00 GMT

Fabrication of Two-Dimensional Material Membranes

Tue, 24 Oct 2023 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.

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

Mon, 23 Oct 2023 00:00:00 GMT

Johnson Matthey Highlights

Mon, 09 Oct 2023 00:00:00 GMT

Potential of Hydrogen Internal Combustion Engine for the Decarbonised Passenger Vehicle

Thu, 05 Oct 2023 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.

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

Wed, 04 Oct 2023 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.

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

Tue, 03 Oct 2023 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.

In the Lab: Artificial Metalloenzymes for Sustainable Chemical Production

Wed, 27 Sep 2023 00:00:00 GMT

Guest Editorial: Industrial Biotechnology

Tue, 19 Sep 2023 00:00:00 GMT

Latest Content

Theoretical Study on Copper Adsorption on ZnO Surfaces

Effect of Hf on the Microstructure and Mechanical Property of Pt-15Ir-xHf-0.5Y Alloy

A New Approach to Ti-HA Bio Composite: Pressure-Assisted Coating on the Antibacterial and Electrochemical Properties of Ti6Al4V

A Comprehensive Exploration of Biomass Gasification Technologies Advancing United Nations Sustainable Development Goals

Autonomous Structural Health Monitoring and Remaining Useful Life Estimation of Floating Offshore Wind Turbine Cables

The Effect of Platinum Single Atoms in Titania for Photocatalytic Applications

“Combustion Chemistry and the Carbon Neutral Future”

“Characterization of Minerals, Metals, and Materials 2023”

Guest Editorial

Johnson Matthey Highlights

Contents

Active Sites of Cu/ZnO-Based Catalysts for CO2 Hydrogenation to Methanol

Ultrafast spectroscopy at the Central Laser Facility

Oxidation Kinetics of FeCr and FeCrAl Alloys: Influence of Secondary Processes

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

“Hydrogen Technologies”

Johnson Matthey Highlights

Editorial: 10th Anniversary of Johnson Matthey Technology Review

Fabrication of Two-Dimensional Material Membranes

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

Johnson Matthey Highlights

Potential of Hydrogen Internal Combustion Engine for the Decarbonised Passenger Vehicle

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

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

In the Lab: Artificial Metalloenzymes for Sustainable Chemical Production

Guest Editorial: Industrial Biotechnology