Upcycling waste polycarbonate plastics into jet fuels over NiCo/C by catalytic tandem hydropyrolysis/hydrodeoxygenation

Chemical upcycling of waste polycarbonate (PC) into jet fuels through catalytic tandem hydropyrolysis/hydrodeoxygenation (THH) is a practical strategy to generate value from polymer wastes. A process which combining hydropyrolysis with vapor phase hydrodeoxygenation (HDO) was proposed in a two-stage pressurized fixed-bed reactor. A cobalt-based Metal-Organic Framework (MOF) derived material supported with nickel was designed for the vapor-phase HDO of phenolic compounds derived from PC hydropyrolysis. The product distribution could be regulated by optimizing reaction pressure in the reactor and catalyst to PC mass ratio. Experimental results showed that the products are all phenolic compounds in the absence of catalysts, while a high yield of jet-fuel range cycloalkanes (100%) was obtained under optimized conditions (7 bar H2 pressure and 5:1 catalyst to PC mass ratio) over NiCo/C. The high HDO activity of NiCo/C depends on the synergistic effect of nickel and cobalt atoms, which facilitates the elimination of phenolic hydroxyl group and hydrogenation of benzene ring. This work puts forward an efficient approach for upcycling PC waste into jet fuels with MOF-derived NiCo/C as a catalyst.