Chen Kaiting, Li Qingwei, Han Xinyu, Rao Cheng, Yang Xiangguang, Zhang Yibo
School of Rare Earths, University of Science and Technology of China, Hefei 230026, China.
Ganjiang Innovation Academy, Chinese Academy of Sciences, No.1, Science Academy Road, Ganxian, Ganzhou, Jiangxi 341000, China.
ACS Appl Mater Interfaces. 2025 Aug 20;17(33):47020-47035. doi: 10.1021/acsami.5c09789. Epub 2025 Aug 7.
Developing efficient low-temperature selective catalytic reduction (CO-SCR) catalysts remains a key challenge in reducing nitrogen oxide (NO) emissions. Here, we report a photothermal-enhanced Rh-Mn/CoAlO heterostructure catalyst that achieves excellent NO conversion (more than 90% at 140 °C) and N selectivity (>80%) under visible to infrared light irradiation. By integration of highly dispersed Rh units with Mn clusters onto a hydrotalcite-derived CoAlO support, the catalyst exhibits synergistic light absorption and dynamic lattice oxygen migration capabilities. Through combined analysis using in situ DRIFTS, XAFS, XPS, EPR, and other techniques, we reveal that Mn doping induces numerous oxygen vacancies and promotes electron transfer between Rh and Mn, facilitating lattice oxygen activation via a mechanism similar to the Mars-van Krevelen mechanism. Light exposure reduces the activation energy and, according to Arrhenius analysis and NO-TPD results, accelerates the decomposition of nitrate intermediates and enhances the conversion rate of nitrous oxide to N. Density functional theory (DFT) calculations confirm that NO is more likely to be generated at the Rh-Mn interface, demonstrating its enhanced low-temperature activation ability for NO. This study innovatively enhances the catalytic performance of CO-SCR using light, providing a sustainable method for reducing low-energy NO emissions.
开发高效的低温选择性催化还原（CO-SCR）催化剂仍然是减少氮氧化物（NO）排放的关键挑战。在此，我们报道了一种光热增强的Rh-Mn/CoAlO异质结构催化剂，该催化剂在可见光至红外光照射下实现了优异的NO转化率（140℃时超过90%）和N选择性（>80%）。通过将高度分散的Rh单元与Mn簇整合到水滑石衍生的CoAlO载体上，该催化剂展现出协同的光吸收和动态晶格氧迁移能力。通过原位漫反射红外傅里叶变换光谱（DRIFTS）、X射线吸收精细结构（XAFS）、X射线光电子能谱（XPS）、电子顺磁共振（EPR）等技术的联合分析，我们揭示了Mn掺杂诱导了大量氧空位，并促进了Rh和Mn之间的电子转移，通过类似于Mars-van Krevelen机理的机制促进了晶格氧的活化。光照降低了活化能，根据阿伦尼乌斯分析和NO程序升温脱附（NO-TPD）结果，加速了硝酸盐中间体的分解，并提高了一氧化二氮向N的转化率。密度泛函理论（DFT）计算证实，NO更有可能在Rh-Mn界面处生成，表明其对NO的低温活化能力增强。本研究创新性地利用光提高了CO-SCR的催化性能，为减少低能量NO排放提供了一种可持续的方法。
