3D Printing of Integrated Metallic Reactor Catalysts: Concept and Application

Selective laser melting can be used to create custom-made monolith reactor components with embedded microscale catalytic sites. Doping with noble metals (0.01–0.04 % of Pt, Ir, Ru, or Rh) gave clean incorporation of the active metal particles metals. Yet catalytic activity was low, due to distribution of the active particles between the surface and the bulk of the monolith. Switching to cobalt enabled doping in higher amounts (1.5–2.0 %) with corresponding increase in activity. Using borohydride hydrolysis as a test reaction, we showed that a combined stainless steel and cobalt monolith was active in both batch and continuous systems, for at least 48 h, albeit with some loss of active material. The advantages and limitations of this catalyst/reactor preparation method are discussed.