Johnson Matthey Technology Review - Volume 62, Issue 4, 2018

An optimal platinum alloy for precision casting was developed by taking 25 possible alloying elements into consideration. In order to rank these elements an equation was designed. The ranking allowed five promising alloy compositions to be identified. From these five alloys arc melted buttons were produced and tested for homogeneity and hardness to ensure their suitability as jewellery alloys. A pyrometer was used to measure solidus temperatures. In a second iteration, the five alloys were further improved and the most promising alloys were cast and compared to a commonly used jewellery alloy: platinum-copper-gallium (PtCuGa). The comparison was based on the melting interval and on microstructural investigations, carried out by scanning electron and optical microscopy, while mechanical properties were determined by tensile testing. Additionally, optical properties such as reflectivity and colour were investigated. After the second iteration two very promising compositions were identified: PtCuFeMnCr and PtCuFePdVY.

This symposium held in Bad Harrenalb, Germany, from 3rd–5th September, 2017, specifically focused on modelling and numerical simulation in automobile exhaust-gas aftertreatment. The purpose of the workshop was to support the exchange of state-of-the-art modelling and simulation techniques and new approaches among researchers, scientists and engineers from industry and academia. The meeting had over 100 registered participants, about 45% from academia and 55% from industry. The scientific programme was composed of four tutorials, plus oral and poster presentations.

This report gives a summary of the oral presentations, which will be divided into five sessions: selective catalytic reduction (SCR), methane oxidation, diesel oxidation catalyst (DOC), diesel particulate filter (DPF) and modelling and performance.

Industrial processes contribute significantly to global carbon dioxide emissions, with iron and steel manufacturing alone responsible for 6% of the total figure. The STEPWISE project, funded through the European Horizon 2020 (H2020) Low Carbon Energy (LCE) programme under grant agreement number 640769, is looking at reducing CO2 emissions in the iron and steel making industries. At the heart of this project is the ECN technology called sorption-enhanced water-gas shift (SEWGS), which is a solid sorption technology for CO2 capture from fuel gases such as blast furnace gas (BFG). This technology combines water-gas shift (WGS) in the WGS section with CO2/H2 separation steps in the SEWGS section. Scaling up of the SEWGS technology for CO2 capture from BFG and demonstrating it in an industrially relevant environment are the key objectives of the STEPWISE project, which are achieved by international collaboration between the project partners towards design, construction and operation of a pilot plant at Swerea Mefos, Luleå, Sweden, next to the SSAB steel manufacturing site.

Exhaust gas recirculation is a widely used technology on conventional vehicles, primarily for lowering emissions of local pollutants. Here we use chemical models to show that an exhaust-gas recirculation loop can be converted into a heat-recovery system by incorporating a catalytic reformer. The system is predicted to be particularly effective for gasoline-fuelled spark ignition engines. The high temperature and low oxygen-content of the exhaust gas mean that endothermic reactions will predominate, when some of the gasoline is injected into the recirculation loop upstream of the reformer. The output of the reformer will, therefore, have a higher fuel heating value than the gasoline consumed. Chemical efficiency calculations, based on the predicted reformer output at chemical equilibrium, indicate that the direct improvement in fuel economy could be as high as 14%. Initial tests using a rhodium reforming catalyst suggest that much of the heat recovery predicted by the thermodynamic models can be achieved in practice, which together with a reduction in throttling may allow a gasoline spark ignition engine to match the fuel economy of a diesel engine.

Oxidative destruction of organic compounds in water streams could significantly reduce environmental effects associated with discharging waste. We report the development of a process to oxidise phenol in aqueous solutions, a model for waste stream contaminants, using Fenton’s reactions combined with in situ synthesised hydrogen peroxide (H2O2). Bifunctional palladium-iron supported catalysts, where Pd is responsible for H2O2 synthesis while Fe ensures the production of reactive oxygen species required for the degradation of phenol to less toxic species is reported. A comparison is made between in situ generated and commercial H2O2 and the effect of phenol degradation products on catalyst stability is explored.

The aim of catalytic wet air oxidation is to use air to remove organic contaminants from wastewater through their complete oxidation, without having to vaporise the water. To date, the widespread exploitation of this process has been held back by the low activity of available catalysts, which means that it has to be operated at above-atmospheric pressure in order to keep the water in the liquid phase at the elevated temperatures required to achieve complete oxidation. Here we present an overview of an ongoing study examining the key requirements of both the active phase and the support material in precious metal catalysts for wet air oxidation, using phenol as the model contaminant. The major outcome to date is that the results reveal a synergy between platinum and hydrophobic support materials, which is not apparent when the active phase is ruthenium.

Atomic force microscopy (AFM) an analytical technique based on probing a surface or interface with a microcantilever, has become widely used in formulation engineering applications such as consumer goods, food and pharmaceutical products. Its application is not limited to imaging surface topography with nanometre spatial resolution, but is also useful for analysing material properties such as adhesion, hardness and surface chemistry. AFM offers unparalleled advantages over other microscopy techniques when studying colloidal systems. The minimum sample preparation requirements, in situ observation and flexible operational conditions enable it to act as a versatile platform for surface analysis. In this review we will present some applications of AFM, and discuss how it has developed into a repertoire of techniques for analysing formulated products at the nanoscale under native conditions.