Selective hydrogenation of acetylene alcohols in a flow reactor.

The project aims to investigate the influence of the size and composition of bimetallic PdZn nanoparticle catalysts on selectivity and activity in the selective hydrogenation of 2-methyl-3-butyn-2-ol. The reaction serves as a model reaction for the hydrogenation of acetylene alcohols, industrially applied the synthesis of i.e. vitamins and fine chemicals. The PdZn nanoparticles are supported on mesoporous titania, which is in turn coated on the walls of fused silica capillaries with an internal diameter of 250µm. The high specific surface area of these microreactors enables fast mass and heat transfer unattainable in conventional reactors. Also, continuous operation gives a higher degree of control of product quality.

The multiple reaction pathways make selectivity to the semi-hydrogenated a challenge, especially at industrially relevant high conversions (>99%). Optimisation of the catalyst can proceed by variation of particle size and composition. The hydrogenation kinetics of several catalyst coatings containing particles of different sizes (1.8–3.1 nm) and compositions (Pd10Zn90–Pd90Zn10) will be studied by varying reaction parameters such as reaction temperature and residence time. Modelling and evaluation of fitted kinetic constants will give valuable insights into reaction mechanisms and the catalyst properties required for optimal hydrogenation performance.

The project also aims at the scale-up of a single reactor capillary to an assembly of several identical capillaries working in parallel.