Yang Shuai, Li Xinyang, Ma Jiawen, Guo Haiwei, Chen Yifeng, Chen Zhao, Ren Gengbo, Ma Xiaodong
Tianjin Key Laboratory of Clean Energy and Pollutant Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China.
Nanoscale. 2022 Jun 1;14(21):7849-7855. doi: 10.1039/d2nr00955b.
The development of cost-efficient catalysts with good catalytic activity is an urgent task for polychlorinated aromatic hydrocarbon (PCAH) oxidation. Herein, atomically dispersed Ru catalysts (denoted as Ru ADCs) proved by aberration corrected high-angle annular dark-field scanning transmission electron microscopy and X-ray absorption spectroscopy were synthesized for PCAH oxidation. The oxidation results showed that 0.2 Ru ADCs exhibited enhanced catalytic activity ( < 250 °C, < 300 °C) compared with the > 300 °C on 0.2 Ru nanoparticles (NPs). Besides, 0.2 Ru ADCs demonstrated high CO yield with >60% CO ratio, along with good stability (>80% conversion for 800 mins). The better performance of 0.2 Ru ADCs was verified by kinetic experiments, in which, the apparent activation energy associated with 0.2 Ru ADCs (50.8 kJ mol) was significantly lower compared with that with 0.2 Ru NPs (80.0 kJ mol). The superior oxidation activity of 0.2 Ru ADCs was also applied to toluene oxidation. H temperature-programmed reduction ensured the stronger interaction of Ru species with the supports in Ru ADCs than that in Ru NPs, thus inhibiting Ru species aggregation and favoring their higher dispersion ensured by CO temperature-programmed desorption. The present work provides a potential strategy to maximize the usage of noble metal catalysts for PCAH oxidation.
开发具有良好催化活性的低成本催化剂是多氯代芳烃（PCAH）氧化的一项紧迫任务。在此，通过像差校正高角度环形暗场扫描透射电子显微镜和X射线吸收光谱证实的原子分散钌催化剂（表示为Ru ADCs）被合成用于PCAH氧化。氧化结果表明，与0.2 Ru纳米颗粒（NPs）上>300°C相比，0.2 Ru ADCs表现出增强的催化活性（<250°C，<300°C）。此外，0.2 Ru ADCs表现出高CO产率，CO比例>60%，同时具有良好的稳定性（800分钟内转化率>80%）。动力学实验验证了0.2 Ru ADCs的更好性能，其中，与0.2 Ru NPs（80.0 kJ mol）相比，与0.2 Ru ADCs相关的表观活化能（50.8 kJ mol）显著更低。0.2 Ru ADCs的优异氧化活性也应用于甲苯氧化。H程序升温还原确保了Ru ADCs中Ru物种与载体的相互作用比Ru NPs中更强，从而抑制Ru物种聚集，并有利于通过CO程序升温脱附确保其更高的分散度。本工作提供了一种潜在策略，以最大限度地利用贵金属催化剂进行PCAH氧化。
