Hubei Key Laboratory of Soil Environment and Pollution Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China.
Hubei Key Laboratory of Soil Environment and Pollution Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China.
J Hazard Mater. 2020 Nov 5;398:122958. doi: 10.1016/j.jhazmat.2020.122958. Epub 2020 May 24.
Cryptomelane-type manganese oxides (OMS-2) have been intensively investigated for application in the catalytic oxidation of carcinogenic benzene, and doping metal ions in the OMS-2 tunnels are widely used for modifying its catalytic activity. In this study, we reported a novel strategy of enhancing catalytic activity of OMS-2 for carcinogenic benzene elimination by tuning Sr concentration in the tunnels. The catalytic activity result revealed that an obvious decrease (△T = 27 °C and △T = 37 °C) in T and T (corresponding to benzene conversions at 50 % and 90 %, respectively; initial benzene concentration was 2000 mg m; contact time was 1.5 s) had been observed by increasing the Sr concentration in the OMS-2 tunnels. The origin of Sr doping effect on catalytic activity was theoretically and experimentally investigated by CO temperature-programmed reduction, O isotope labeling, and density functional theory calculations. The result confirmed that increasing Sr concentration in the tunnels not only promoted the lattice oxygen activity, but also facilitated the generation of more oxygen vacancy defects, thus considerably improving the catalytic activity of OMS-2.
钙钛矿型锰氧化物（OMS-2）因其在催化氧化致癌苯方面的应用而受到广泛研究，并且在 OMS-2 隧道中掺杂金属离子广泛用于修饰其催化活性。在本研究中，我们报道了一种通过调节隧道中 Sr 浓度来提高 OMS-2 对致癌苯消除的催化活性的新策略。催化活性结果表明，通过增加 OMS-2 隧道中的 Sr 浓度，观察到 T 和 T 的明显降低（△T = 27°C 和 △T = 37°C；初始苯浓度为 2000mg m；接触时间为 1.5s）。通过 CO 程序升温还原、O 同位素标记和密度泛函理论计算对 Sr 掺杂对催化活性的影响进行了理论和实验研究。结果证实，增加隧道中的 Sr 浓度不仅促进了晶格氧的活性，而且还促进了更多氧空位缺陷的产生，从而显著提高了 OMS-2 的催化活性。
