Industrial sources, such as steel and power activities continue to emit substantial amounts of CO, but have not received the same level of attention as mobile sources due to a lack of relevant regulations. This work reports that a commercial Pt/Al2O3 catalyst used in vehicle CO catalytic converters may face severe selenium (Se) poisoning deactivation from industrial sources. The turnover frequency (TOF) of the Pt/Al2O3 catalyst (250 °C) decreased from 2.18 s−1 to 0.12 s−1 with only 0.49 wt% (ICP) Se deposition. Se deposition causes the Pt 5d orbital shift to a higher energy state, raising the oxidation state of platinum. As a result, the back-donation from the 5d electrons of Pt to the 2π* antibonding orbital of the adsorbed CO molecule is inhibited, weakening the bonding between Pt/Al2O3 and the CO antibonding orbital, thereby significantly reducing CO activation ability. DRIFTS results, combined with apparent and microscopic kinetics, indicate that the surface of Se deposited Pt/Al2O3 catalyst remains O* available (500 K, θO* = 0.16), and the rate-controlling step changes from O2 + 2* → 2O* to CO + * → CO*. The work suggests that the application of CO catalytic oxidation technology for industrial source should fully consider the toxic effect of Se, but is often neglected.

中文翻译：

---

硒调制的 Pt/Al2O3 电子结构在催化 CO 氧化过程中诱导失活


钢铁和电力活动等工业源继续排放大量一氧化碳，但由于缺乏相关法规，没有得到与移动源同等程度的关注。这项工作报道了用于车用 CO 催化转化器的商用 Pt/Al2O3 催化剂可能面临严重的工业来源硒 （Se） 中毒失活。Pt/Al2O3 催化剂的周转频率 （TOF） （250 °C） 从 2.18 s-1 下降到 0.12 s-1，只有 0.49 wt% （ICP） 的 Se 沉积。Se 沉积导致 Pt 5d 轨道移动到更高的能量态，从而提高铂的氧化态。结果，Pt 的 5d 电子向吸附的 CO 分子的 2π* 反键轨道的反向捐赠受到抑制，削弱了 Pt/Al2O3 与 CO 反键轨道之间的键合，从而显着降低了 CO 活化能力。DRIFTS 结果与表观和微观动力学相结合，表明 Se 沉积的 Pt/Al2O3 催化剂表面保持 O* 可用 （500 K，θO* = 0.16），速率控制步长从 O2 + 2* → 2O* 变为 CO + * → CO*。该工作提示，CO催化氧化技术在工业源中的应用应充分考虑Se的毒性作用，但往往被忽视。