Tuning the Cu/SiO2 wettability features for bio-derived platform molecules valorization

A simple organosilane-grafting protocol has been used for the preparation of a copper heterogeneous catalyst with tunable wettability properties. A series of Cu/SiO2 trietoxyoctylsilane-modified systems with gradually reduced alcoholphilicity has been used in the hydrogenation of the platform molecule gamma-valerolactone into 1,4-pentandiol, a valuable biobased monomer. The surface modification obtained with the proposed procedure allows to significantly increase the selectivity (99%) of the process and therefore the yield (80%) in the desired diol. Several characterization techniques (static contact angle, ATR, CP-MAS solid state NMR, pyridine and ammonia adsorption) put in light the modification of the surface while preserving the hydrogenation activity of the metallic phase. The results obtained show the opportunity given by this simple catalytic system in combining the activity of the copper phase and the modified polarity of the surface.