Mo Fan, Zhou Qixing, Wang Pengfei, Liu Weitao, Yin Chuan, Hou Zelin, Xue Wendan, Wang Qi, Wang Jianling, Zheng Tong, Tao Zongxin, Li Xiang
SEP Key Laboratory of Eco-industry, School of Resources and Civil Engineering, Northeastern University 11 Wenhua Road, Heping District Shenyang 110819 P.R. China.
Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education)/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Carbon Neutrality Interdisciplinary Science Center, College of Environmental Science and Engineering, Nankai University Tianjin 300350 China
Chem Sci. 2025 Aug 4. doi: 10.1039/d5sc04662a.
The development of hydrogen- and solvent-free catalytic systems for plastic valorization requires precise control over metal speciation to enhance both catalytic efficiency and selectivity. Ru atomic clusters (ACs) on HZSM-5 zeolite show a turnover frequency of 52.71 mg mg h in low-density polyethylene (LDPE) conversion, a fivefold increase compared to traditional nanoparticles (NPs) at 10.63 mg mg h. This improved catalytic performance is further evident in cyclohexane dehydro-aromatization, where atomic-scale Ru sites exhibit a 17.8-fold activity increase (544.34 30.48 μM mg h), linking subnanometric structures to reaction pathway selectivity. Mechanistic analysis highlights two key effects: (1) optimized interactions between isolated Ru sites and intermediates lower dehydrogenation barriers, and (2) reduced cyclization energy barriers compared to NPs. Process optimization leads to 87% LDPE conversion with 69% aromatic selectivity, maintaining 70% efficiency across various polyolefins (including high-density PE and ultra-high-molecular-weight PE) and polystyrene. A techno-economic analysis shows the potential of AC catalysts, predicting a net present value of 1.78 million over five years, compared to an annual loss of 8.17 million for NPs. This study demonstrates the critical role of metal dispersion and acid-metal balance, forming the basis for a sustainable plastic-to-aromatics process with strong economic viability.
开发用于塑料增值的无氢和无溶剂催化体系需要精确控制金属形态，以提高催化效率和选择性。HZSM-5沸石上的钌原子簇（ACs）在低密度聚乙烯（LDPE）转化中显示出52.71 mg mg h的周转频率，与传统纳米颗粒（NPs）在10.63 mg mg h时相比提高了五倍。这种改进的催化性能在环己烷脱氢芳构化中更加明显，其中原子尺度的钌位点活性提高了17.8倍（544.34±30.48 μM mg h），将亚纳米结构与反应路径选择性联系起来。机理分析突出了两个关键作用：（1）孤立的钌位点与中间体之间的优化相互作用降低了脱氢势垒，（2）与NPs相比，环化能垒降低。工艺优化实现了87%的LDPE转化率和69%的芳烃选择性，在各种聚烯烃（包括高密度聚乙烯和超高分子量聚乙烯）和聚苯乙烯中保持70%的效率。技术经济分析显示了AC催化剂的潜力，预测五年内净现值为178万，而NPs每年损失817万。这项研究证明了金属分散和酸-金属平衡的关键作用，为具有强大经济可行性的可持续塑料制芳烃工艺奠定了基础。
