Huang Jiangli, Lin Jia, Chen Xiaohua, Zheng Yong, Xiao Yihong, Zheng Ying
College of Chemistry and Materials Science, Fujian Provincial Key Laboratory of Advanced Materials Oriented Chemical Engineering, Fujian Normal University, Fuzhou 350007, Fujian, P. R. China.
National Engineering Research Center of Chemical Fertilizer Catalyst, Fuzhou University, Fuzhou 350002, Fujian, P. R. China.
ACS Appl Mater Interfaces. 2022 Apr 13;14(14):16233-16244. doi: 10.1021/acsami.2c01420. Epub 2022 Apr 4.
The preparation of palladium-based catalysts with both high catalytic activity and hydrothermal stability currently appears as a critical topic in methane combustion. Herein, we propose a facile strategy to boost the performance of SnO-CeO binary oxide supported palladium catalysts by tuning the composition of supports. The coexistence of SnO and CeO phases in an appropriate ratio is favorable for the formation of both PdCeO and PdSnO solid solutions due to the reduced crystallite size. This unique microstructure could enhance the metal-support interaction to stabilize the active PdO phase and promote its reoxidation, meanwhile generating more oxygen vacancies to improve the reducibility of PdO. On account of the facilitated conversion of PdO ↔ Pd, coupled with the low-temperature dissociation of methane promoted by abundant active oxygen species, the Pd/5Sn5Ce catalyst exhibits a superior catalytic activity with a of ca. 360 °C, a robust stability under both dry and wet conditions, and an excellent thermal stability during heating-cooling light-off tests.
目前，制备具有高催化活性和水热稳定性的钯基催化剂是甲烷燃烧领域的一个关键课题。在此，我们提出了一种简便的策略，通过调整载体组成来提高SnO-CeO二元氧化物负载钯催化剂的性能。由于微晶尺寸减小，适当比例的SnO和CeO相共存有利于PdCeO和PdSnO固溶体的形成。这种独特的微观结构可以增强金属-载体相互作用，以稳定活性PdO相并促进其再氧化，同时产生更多氧空位以提高PdO的还原性。由于PdO↔Pd的转化更容易，加上大量活性氧物种促进甲烷的低温解离，Pd/5Sn5Ce催化剂表现出优异的催化活性，T90约为360℃，在干燥和潮湿条件下都具有强大的稳定性，并且在加热-冷却起燃测试中具有出色的热稳定性。
