Continuous flow semi-hydrogenation of alkynes using 3D printed catalytic static mixers

The semi-hydrogenation of 2-methyl-3-butyn-2-ol and 2-butyne-1,4-diol over three sets of catalytic static mixers coated with commercial and non-commercial palladium and nickel catalysts has been investigated and optimised over a range of conditions, achieving excellent results of up to 87 % in alkene yield, selectivities above 90 % and space-time yields of up to 3.0 kg L−1 h−1. We investigated the effects of process parameters including pressure, temperature, residence time and concentration on the rate and selectivity of hydrogenation for the different catalytic static mixers tested. The most prominent influence was observed for changes in reactor pressure, whereby higher values result in an increase in conversion but a decrease in selectivity.