Developing Silicalite-1 Encapsulated Ni Nanoparticles as Sintering-/Coking-Resistant Catalysts for Dry Reforming of Methane

An encapsulation strategy has been employed to improve stability of Ni-based catalysts. Nickel nanoparticles encapsulated in the silicalite-1 were prepared using different methods to investigate the effect of synthesis protocol on properties of catalysts, such as encapsulation degree and Ni dispersion, and anti-coking/-sintering performance in DRM. The Ni@SiO 2 - S1 catalysts presented fully encapsulation of Ni NPs by the zeolite framework with small particle sizes (2.9 nm) and strong metal-support interaction, which hinder the aggregation of Ni and carbon deposition. Thus, it showed stable CO 2 /CH 4 conversions of 80% and 73% with negligible metal sintering and coking deposition over 28h. The catalysts developed by post-treatment and hydrothermal methods showed co-existence of Ni phase on the internal and external surface, i.e. incomplete encapsulation with large Ni particles, contributing to Ni sintering and coking. The correlation of synthesis-structure-performance sheds light on the design of coking-/sintering-resistant encapsulated catalysts for DRM