National Engineering Laboratory for Green Chemical Productions of Alcohols, Ethers and Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China.
Nanoscale. 2018 Jul 26;10(29):14031-14038. doi: 10.1039/c8nr02588f.
During partial oxidation of methane (POM), the greatest challenge is to maintain the thermal stability of the catalyst at high temperatures. One of the most effective ways to improve thermal stability is to construct core-shell structure. Herein, using a microemulsion method, we synthesized a core-shell Ni/nanorod-CeO2@SiO2 catalyst, in which the Ni nanoparticles were supported on the CeO2 nanorods and encapsulated by SiO2 shells. Based on a series of characterizations, we found that the Ni particles are of nanosize (2.2 nm) and the thickness of the SiO2 shell is about 8 nm in the core-shell catalyst. Moreover, the Ni/nanorod-CeO2@SiO2 catalyst can perfectly maintain rod-like structures of the CeO2 support and enhance interaction between the metal Ni and CeO2, significantly reducing the sintering of metal Ni particles at high temperatures. Therefore, the as-prepared Ni/nanorod-CeO2@SiO2 catalyst shows high catalytic activity and good thermal stability during the POM reaction.
在甲烷部分氧化（POM）过程中，最大的挑战是在高温下保持催化剂的热稳定性。提高热稳定性的最有效方法之一是构建核壳结构。在此，我们使用微乳液法合成了核壳结构的 Ni/纳米棒-CeO2@SiO2 催化剂，其中 Ni 纳米颗粒负载在 CeO2 纳米棒上，并被 SiO2 壳包裹。通过一系列的表征，我们发现核壳催化剂中 Ni 颗粒的尺寸为纳米级（2.2nm），SiO2 壳的厚度约为 8nm。此外，Ni/nanorod-CeO2@SiO2 催化剂可以完美地保持 CeO2 载体的棒状结构，并增强金属 Ni 和 CeO2 之间的相互作用，显著降低了金属 Ni 颗粒在高温下的烧结。因此，所制备的 Ni/nanorod-CeO2@SiO2 催化剂在 POM 反应中表现出高催化活性和良好的热稳定性。
