Ni-Cu Alloy Nanoparticles Confined by Physical Encapsulation with SiO and Chemical Metal-Support Interaction with CeO for Methane Dry Reforming.

Fabrication of sintering- and carbon-free Ni catalysts for methane dry reforming (MDR), which is attractive to upgrade greenhouse gases CH and CO, is challenging. In this work, we innovatively synthesized Ni-Cu alloy nanoparticles confined by physical encapsulation and chemical metal-support interaction (MSI); the synergism of alloy effect, size effect, MSI, and confinement effect in the catalysts gave high rates of CH and CO of 6.98 and 7.16 mmol/(gs), respectively, at 1023 K for 50 h. The rates were 2-3 times enhanced compared to those in the literature. XRD, TEM, H-TPR, and so forth revealed that the alloy effect, size effect, and MSI of Ni-Cu and CeO enhanced the MDR activity; MSI promoted the ceria surface lattice oxygen mobility and generated more oxygen vacancies, almost completely gasifying carbon deposits; chemical confinement from MSI and physical confinement from SiO nanospheres realized sintering-free alloys and CeO nanoparticles. The synergistic approach provides a universal strategy for sintering- and carbon-free Ni catalyst design for MDR reaction.