Polyethylene Upgrading to Liquid Fuels Boosted by Atomic Ce Promoters

Abstract

Hydrocracking catalysis is a key route to plastic waste upgrading, but the acid site‐driven C‐C cleavage step is relatively sluggish in conventional bifunctional catalysts, dramatically effecting the overall efficiency. We demonstrate here a facile and efficient way to boost the reactivity of acid sites by introducing Ce promoters into Pt/HY catalysts, thus achieving a better metal‐acid balance. Remarkably, 100 % of LDPE can be converted with 80.9 % selectivity of liquid fuels over the obtained Pt/5Ce‐HY catalysts at 300 °C in 2 h. For comparison, Pt/HY only gives 38.8% of LDPE conversion with 21.3% selectivity of liquid fuels. Through multiple experimental studies on the structure‐performance relationship, the Ce species occupied in the supercage are identified as the actual active sites, which possess remarkably‐improved adsorption capability towards short‐chain intermediates.

Hydrogen Bubbles: Harmonizing Local Hydrogen Transfer for Efficient Plastic Hydro-Depolymerization

“…The advent of synthetic plastics derived from petroleum has conferred considerable conveniences upon modern society. , In the year 2019 alone, an astonishing 460 million tons of plastic products was globally manufactured . However, the disconcerting reality unveils that less than 20% of plastic waste undergoes responsible recycling. − This substantial volume of improperly disposed plastic waste significantly contributes to environmental pollution and signifies a wasteful depletion of valuable resources. − In response to this challenge, the hydro-depolymerization of waste plastics into small hydrocarbons emerges as a commendable recycling avenue (Figure a). − For example, hydrocracking of waste polyolefins can receive isomerized alkanes, ,, and PET wastes can be subjected to hydrodeoxygenation to yield value-added BTX …”