Additive manufacturing is having a dramatic impact on research and industry across multiple sectors, but the production of additively manufactured systems for ultra-high vacuum applications has so far proved elusive widely been considered impossible. We demonstrate first chamber operating at pressure below 10−10 mbar, measured via an ion pump current reading, show that corresponding upper limit...

Under ultra-high-vacuum conditions, precoverage of a palladium(ll1) surface with hydrogen does not affect either the kinetics or the extent of acetylene uptake at 175 K. The subsequent reactive behavior of the system is however radically altered. Benzene formation is strongly suppressed, the transformation of adsorbed acetylene to another species (@-phase) is enhanced, and the yield of ethylene...