Université de Lille Nord de France, 59 000 Lille (France), CNRS UMR-8181, Unité de Catalyse et de Chimie du Solide, UCCS, 59655 Villeneuve d'Ascq (France).
ChemSusChem. 2014 Feb;7(2):631-7. doi: 10.1002/cssc.201300718. Epub 2013 Dec 9.
The in situ autocombustion synthesis route is shown to be an easy and efficient way to produce nanoscaled nickel oxide containing lanthanum-doped mesoporous silica composite. Through this approach, ~3 nm NiO particles homogeneously dispersed in the pores of silica are obtained, while lanthanum is observed to cover the surface of the silica pore wall. Subsequent reduction of such composite precursors under hydrogen generates Ni(0) nanoparticles of a comparable size. Control over the size and size distribution of metallic nanoparticles clearly improved catalytic activity in the methane dry reforming reaction. In addition, these composite materials exhibit excellent stability under severe reaction conditions. This was achieved through the presence of LaOx species, which reduced active-site carbon poisoning, and the confinement effect of the mesoporous support, which reduced metallic particle sintering.
原位自燃烧合成路线被证明是一种制备含镧掺杂介孔氧化硅纳米复合的简单高效的方法。通过这种方法，可以得到~3nm 的 NiO 颗粒均匀分散在氧化硅的孔中，而镧则被观察到覆盖在氧化硅孔壁的表面上。随后，在氢气下还原这种复合前体，生成尺寸相当的 Ni(0)纳米颗粒。对金属纳米颗粒尺寸和尺寸分布的控制明显提高了甲烷干重整反应的催化活性。此外，这些复合材料在苛刻的反应条件下表现出优异的稳定性。这是通过存在 LaOx 物种来实现的，LaOx 物种减少了活性位的碳中毒，以及介孔载体的限域效应，减少了金属颗粒的烧结。
