Design of a carbon-resistant Ni@S-2 reforming catalyst: Controllable Ni nanoparticles sandwiched in a peasecod-like structure

• Published in: Applied catalysis. B, Environmental Environmental, 2021-03, Vol.282, p.119546, Article 119546
• Main Authors: Wang, Jiyang, Fu, Yu, Kong, Wenbo, Jin, Feikai, Bai, Jieru, Zhang, Jun, Sun, Yuhan
• Format: Article
• Language: English
• Subjects: Barriers; Carbon; Carbon dioxide; Carbon resistance; Catalysts; Chemical synthesis; Confinement; Copolymerization; Deposition; Dry reforming of methane; Dual confinement; Methane; Micropore; Nanocomposites; Nanoparticles; Nickel; Nickel phyllosilicate; Reforming; Silicalite; Silicon substrates; Sintering; Stability; Strong interactions (field theory); Ultrafines
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2020.119546

[Display omitted] •In-situ confinement growth of Ni nanoparticles in peasecod-like catalyst.•The different sizes of Ni nanoparticles can be precisely controlled.•Abundant micropores throughout zeolite fully exposed Ni0 active sites.•Ni@S-2 catalyst exhibited superb sintering and carbon resistance. Ni-based catalysts for dry reforming of methane (DRM) suffer from the issue of carbon deposition and sintering. In this study, ultrafine nickel nanoparticles (NPs) embedded in the microporous silicalite-2 (S-2) with a peasecod-like structure was prepared by a facile one-pot approach. The size of Ni NPs (ca. 2, 4, 6 and 8 nm) can be precisely controlled by the degree of Ni-O-Si copolymerization. The obtained Ni@S-2 catalyst with Ni NPs size of 2.6 nm exhibited superior activity and stability with no carbon deposition under 650 °C, CH4:CO2 = 1:1 for 50 h. The layered walls of micropores of S-2 posted steric physical barriers against the migration of Ni NPs. Meanwhile, the strong interaction between active Ni and substrate (Ni-O-Si) provided chemical confinement for anti-sintering. This dual physical-chemical confinement strategy to synthesize catalyst with active Ni° sandwiched between layers of tetrahedral SiO4 provides a promising technique for designing other stable metal nanocomposites.