Xiang Li, Wang Chunqi, Nie Guo, Lou Menghe, Luo Xueqing, Ding Junying, Li Renna, Wu Zhongbiao, Weng Xiaole
State Key Laboratory of Soil Pollution Control and Safety, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, P. R. China.
ZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou 311200, P. R. China.
Environ Sci Technol. 2025 Jul 1;59(25):13073-13084. doi: 10.1021/acs.est.5c03547. Epub 2025 Jun 18.
SO impurity, widely existing in industrial exhaust, is a typical deactivator in many catalytic reactions. The poisoning mechanism of SO on the active sites of catalysts has been well acknowledged, yet the role of support in sulfur-tolerant catalysis remains elusive. Herein, TiO, AlO, and CeO carriers were selected to unveil the sulfur resistance mechanism of Pd-based catalysts in catalytic CO oxidation. We showed that Pd/TiO effectively terminated continuous sulfidation, achieving 100% CO conversion at 175 °C for 200 h under SO and HO exposure. This exceptional sulfur tolerance was attributed to the formation of a distinct tridentate sulfate structure on the PdO nanoparticles, facilitated by the moderate reducibility and strong acidity of Pd/TiO. In contrast, Pd/AlO and Pd/CeO remained only ∼70 and 5% efficiency, accompanied by the abundant formation of Pd-related bidentate and Ce-related tridentate sulfate species, respectively. Combined experimental and theoretical analyses revealed the distinct in situ-formed tridentate Pd-SO coordination over Pd/TiO regulated the local electronic distribution, effectively mitigating the affinity of the catalyst to SO while preserving the redox capability and reactivity of oxygen species. Our findings are crucial for advancing sulfur-tolerant catalysis, offering valuable strategies for rationally designing robust catalysts to overcome both economic and environmental challenges in industrial applications.
SO杂质广泛存在于工业废气中，是许多催化反应中的典型失活剂。SO对催化剂活性位点的中毒机理已得到充分认识，但载体在耐硫催化中的作用仍不清楚。在此，选择TiO、AlO和CeO载体来揭示Pd基催化剂在催化CO氧化中的抗硫机理。我们发现，Pd/TiO有效地终止了连续硫化，在SO和HO暴露下，于175°C实现了200小时的100%CO转化率。这种卓越的耐硫性归因于PdO纳米颗粒上形成了独特的三齿硫酸盐结构，这得益于Pd/TiO适度的还原性和强酸性。相比之下，Pd/AlO和Pd/CeO的效率仅分别保持在约70%和5%，同时分别大量形成了与Pd相关的双齿和与Ce相关的三齿硫酸盐物种。结合实验和理论分析表明，Pd/TiO上原位形成的独特三齿Pd-SO配位调节了局部电子分布，有效降低了催化剂对SO的亲和力，同时保持了氧物种的氧化还原能力和反应活性。我们的发现对于推进耐硫催化至关重要，为合理设计坚固的催化剂提供了有价值的策略，以克服工业应用中的经济和环境挑战。
