Catalysis and Reaction Engineering

Hydrogenation processes are pivotal and prevalent in the chemical industry, heavily involved in processes, such as organic synthesis and fuel production. From a sustainable perspective, reactions must be carried out with heterogeneous catalysts and when possible in flow mode. However, this creates significant difficulties for catalyst preparation and study, in particular when reactions are carried out in the liquid phase and under high pressure. Herein, we present a research strategy to modify catalysts and study the effects of the modification in their catalytic performance in the same reactor, which we labelled as on-the-fly catalyst modification. The methodology permits screening and modification of a parent catalyst in a single reactor, enabling rapid evaluation of the modification effectiveness. Moreover, it potentially allows for a deeper understanding of structure-property relations that can be used in catalyst design, since the on-the-fly methodology helps to isolate a single factor influencing catalysis in part by minimizing differences that can arise from carrying out synthesis and evaluation in different vessels or environments. Herein, we review the developments on catalyst surface functionalization with an eye toward approaches that can be adapted for on-the-fly catalyst modification, as a way to understand and improve catalytic performance. We focused our efforts on heterogeneous systems composed of

nano-nickel particles supported polymeric resins, which we modified post-synthetically to enhance their catalytic activity and/or tailor selectivity to the desired product. The systems were tested on industrially relevant chemoselective hydrogenation of unsaturated aldehydes and ketones.