Combined CVD-PVD coating: Metal particles on BDD
The Power2Hype project is innovating hydrogen peroxide production through a novel combined Chemical Vapour Deposition (CVD) and Physical Vapour Deposition (PVD) coating process. By integrating boron-doped diamond (BDD) with metallic catalyst particles, the project aims to enhance the electrochemical production of hydrogen peroxide.
Diamond CVD-coatings (Chemical Vapour Deposition) combined with metallic PVD-layers (Physical Vapour Deposition) are a key-component for the Power2HyPe project. This material mix wants to integrate boron-doped diamond (BDD) with metallic catalyst particles for the selective production of hydrogen peroxide. To enable this technology, the diamond group of the chair WTM of Friedrich-Alexander Universität Erlangen-Nürnberg is building a new and upscaled reactor that will reach new levels of both area, power and complexity for possible mixed CVD-PVD-coating processes.
The hot-filament reactor is a used machine that has been completely refurbished by our group and comprises two processing chambers with a combined coating area of 5000 cm2 where substrates can be coated at temperatures between 10 °C (PVD) and 950 °C (CVD). To achieve this, a complex cooling system of the reactor is necessary as well as the resistive heating via the filaments with a power of 100 kW-DC. The desired process atmosphere is adjusted from hydrogen, methane, trimethyl borate and noble gases in a pressure range between 10-3 – 800 mbar.
Integrated into this CVD coating system is a PVD sputter array, which allows for the additional deposition of metallic particles or layers – these are supposed to act as (additional) catalytic centres in the electrochemical processes for the production of hydrogen peroxide or other chemicals. Envisioned is the use of titanium, copper, cobalt, nickel and tungsten as target materials to form active particles and layers in the nanometre range. The excitation of the plasma is done via a 200 – 2000 V voltage source. For more advanced processes an in-line heat treatment is possible to improve the adhesion and performance of the metallic particles.
In the Power2HyPe project, our coating plant is used to manufacture boron-doped diamond (BDD) with a variety of different properties regarding doping level, crystallinity and sp3-content for catalyst screening (à WP2), combined coatings of metal particles on BDD (à WP3) and the upscaling of both coating types (à WP4) to reach an industrial standard procedure for later transfer to serial production.
