PO43-coordinated Co2+species on yttrium phosphate boosting the valorization of ethanol to butadiene
Upgrading of sustainable ethanol into C4 olefins by C-C coupling contributes to alleviating the de-pendency towards petroleum.The reaction network consists several key steps,whereas dehydra-tion often competes with dehydrogenation over acidic catalyst.Herein,we report a designed bifunc-tional Co-YPO4 catalyst with balanced active sites for dehydrogenation and condensation that can directly catalyze ethanol to butadiene.The YPO4 can stabilize Co2+species to form highly dispersed[Co-O-P]sites,which catalyze ethanol dehydrogenation to acetaldehyde.Additionally,the YPO4 surface exposed Y3+site,as Lewis acid center,which can effectively catalyze C-C coupling reaction.The addition of cobalt enhances the ethanol dehydrogenation process while reducing the surface acidity,thus inhibiting the formation of dehydration products and promoting the formation of buta-diene.Kinetic measurements suggest that the rate-limiting step is the dehydrogenation of ethanol to acetaldehyde.The synthesized Co-YPO4 shows a 68.5％selectivity of butadiene under a conversion of 78.2％at 350 ℃ and a weight hourly space velocity of 1.0 gC2H5OH·gCat.-1·h-1.
万方数据
