Renewable and low-carbon hydrogen will contribute to a future climate-neutral economy as a fuel, clean energy carrier and feedstock. One of the main concerns when considering its production by the present proton exchange membrane water electrolysers (PEMWE) is the use of scarce and expensive noble metals as catalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), because they contribute to increase the cost of the technology. Several strategies have been developed to overcome this drawback, such as optimising the catalyst loading in the electrodes and alloying or using alternative catalyst supports, always with the aim to maintain or even increase electrolyser performance and durability. In this review, we examine the latest developments in HER and OER catalysts intended for practical PEMWE systems, which point in the short term to the use of platinum and iridium nanoparticles highly dispersed at low loadings on conductive non-carbon supports.

Bushings made of platinum-rhodium alloys are a key component in glass fibre production. While bushings have grown in size and functionality since their introduction in the early 20th century, manufacturing constraints still limit their full potential. Both in terms of design and quality, traditional manufacturing methods such as milling, drilling and welding limit the potential of precious metal bushings. The technical feasibility of the use of additive manufacturing for the production of bushings is greatly dependent on the material properties. For the purpose of this work, an additively manufactured alloy consisting of 90 wt% platinum and 10 wt% rhodium (PtRh10) is investigated with regard to density, electrical resistivity, creep performance and the contact angle of E-glass on the PtRh10 samples.

Additive manufacturing of jewellery alloys has been actively investigated for the past 10 years. Limited studies have been conducted on gold and platinum jewellery alloys. Platinum is of increased interest due to the technological challenges in investment casting. In the present paper, typical platinum jewellery alloys have been tested by laser track experiments on sheet materials. The effect of alloy composition on width and depth of the laser tracks was studied by metallography. Optimum parameters of the laser powder bed fusion (PBF-LB) process were determined for a typical 950Pt jewellery alloy by the preparation of dedicated test samples. Densities of >99.8% were reached for a wide range of processing parameters. However, for real jewellery parts the resulting density was found to depend significantly on the part geometry and on the chosen support structure. The supports must take into account the geometrical orientation of the part relative to the laser build direction and the orientation on the build plate. Local overheating gives rise to porosity in these areas. Therefore, the supports play an important role in thermal management and must be optimised for each part. The design of suitable supports was successfully demonstrated for a typical jewellery ring sample.

Jewellery-specific standardised tests as well as bulk metallic glass (BMG)-specific testing methods were performed on a series of platinum-based BMGs with and without phosphorus, to evaluate their suitability as jewellery items. Their mechanical properties (elasticity, Young’s modulus and yield stress) were determined by three-point beam bending measurements. Hardness, wear and corrosion resistance were tested in comparison to state-of-the-art crystalline platinum-based jewellery alloys. The platinum-BMG alloys exhibit elastic elongation of about 2%. Compared to conventional crystalline platinum-alloys, their fracture strength of ca. 2 GPa and their hardness of ca. 450 HV1 is four and two times higher, respectively. However, the BMGs show less abrasion resistance in the pin-on-disc test than the conventional benchmark alloys due to adhesive wear and microcracking. Regarding the corrosion resistance in simulated body fluids, the BMG alloys reveal a slightly higher release of metals, while the tarnishing behaviour is comparable to the benchmark alloys. The phosphorus-free platinum-BMG alloy showed pronounced tarnishing during exposure to air at elevated temperature. The outstanding thermoplastic formability, a special feature of amorphous metals that can be crucial for enabling novel and filigree designs, was determined and quantified for all BMG alloys.