Stability and regeneration of Cu-ZrO2 catalysts used in glycerol hydrogenolysis to 1,2-propanediol

A series of Cu–ZrO2 catalysts with different copper contents have been prepared by the coprecipitation method. Their catalytic behavior was studied for glycerol hydrogenolysis reaction to obtain 1,2-propanediol (1,2-PDO) joint to deactivation mechanism and regeneration protocols. A number of physical chemical techniques as X-ray diffraction (XRD), evolved gas analysis by mass spectrometry (EGA-MS), temperature programmed reduction (TPR), X-ray photoelectron spectroscopy (XPS) and chemical analysis have been used to characterize the precursors, activated and spent catalysts. Cu–ZrO2 catalysts with higher atomic ratio Cu/Zr showed higher selectivity while glycerol conversion values were not significantly changed. In terms of stability a decreasing of yield to 1,2-PDO due to a decrease of its selectivity was observed with the number of cycles. The main cause of deactivation was associated to the progressive formation of organic deposits on the surface of catalyst. A regeneration process highly efficient, where almost complete recovery of yield to 1,2-PDO shown by the fresh catalyst was reached, has been identified.Financial support from Spanish Ministry of Science and Innovation (ENE2009-12743-C04-01 and RYC-2010-06067) and Autonomous Government of Madrid (S2009/ENE-1660, CARDENER-CM partly funded by FSE funds) is gratefully acknowledged. D.D.M. thanks the Spanish Ministry of Education for her FPU fellowship.Peer Reviewe