Efficient Hydrocracking of Waste Polyethylene into Branched Liquid Fuels over Low Pt-loaded Nb2O5 Catalyst.

Catalytic hydrocracking of polyethylene to branched liquid fuels has drawn particular attention. Here, bifunctional Pt/Nb₂O₅ catalysts with different Pt loadings were prepared for polyethylene hydrocracking. It was found that the low-loading Pt/Nb₂O₅ catalysts exhibited significantly higher catalytic activity than those of high-loading Pt/Nb₂O₅ catalysts, with the 0.2Pt/Nb₂O₅ catalyst having the best catalytic performance (79.2 % yield of liquid fuels (C₅-C₁₉) with branched alkanes accounting for 85.2 %). Detailed characterizations revealed that the activation of H₂ played a crucial role in the efficient hydrocracking of polyethylene. The 0.2Pt/Nb₂O₅ catalyst, with highly dispersed Pt nanoclusters on the surface, facilitated the highly active H^δ- species formation, thereby enhancing hydrocracking activity. This work highlights the importance of H₂ activation in the hydrocracking of polyethylene and provides insights for the design of efficient catalysts.