Engineering porous Beta zeolite-encapsulated nickel catalyst for waste polyolefins upcycling
Jiahui Zhan, Lin Li, Ruihong Dai, Baohuan Wei, Hu Luo, Rongfei Cong, Haozhi Zhou, Lin Xia, Xiaofang Liu, Shunan Zhang, Shunan Zhang, Shicheng Zhang, Shicheng Zhang, Hui Wang, Yuhan Sun
Abstract
Upcycling plastic wastes through hydrocracking represents an efficient and promising way to produce high-value fuels and chemicals, which faces significant challenges using non-noble metal catalysts . Here, we reported a closed-loop strategy using 10Ni@Beta catalyst to convert low-density polyethylene (LDPE) into naphtha (C 5 -C 9 hydrocarbons), a major feedstock to reproduce polyolefins . The hierarchically porous Beta zeolite was constructed while encapsulating 10 % Ni loading through controlled dissolution-recrystallization. An 88.0 % liquid yield was obtained and the selectivity of naphtha reached 99.1 % at 250 °C within 2 h reaction, surpassing previously reported Pt-based catalysts. The engineered meso-microporous architecture with confined Ni nanoparticles mimicked the mechanism of enzyme-catalyzed process, where the initial cracked LDPE fragments at surface acid were selectively transferred into mesopore channels and further screened by micropores with suitable size to contact Ni sites for hydrogenation. This designed porous catalyst matched the tandem catalytic process of multiple real-life polyolefins , enabling the industrial upcycling of plastic wastes.