Enhanced performance for DRM over encapsulated structure catalyst with
high dispersion of Ni in silicalite-2 shell
Novel structure catalyst with Ni nanoparticles highly dispersed in
silicalite-2 zeolite (S2) was designed and synthesized via a
micro-emulsion method followed by solvent-free crystallization route for
dry reforming of methane (DRM). Compared with Ni-SiO2 catalyst without
crystallization step, Ni/S2 by impregnation method and Ni@S2 prepared by
directly crystallization (Ni@S2-O), the Ni@S2-two steps (Ni@S2-T)
catalyst exhibited optimal catalytic activity and stability. No activity
loss was observed during 70 h at high GHSV of 240000 mL g-1h-1.
Meanwhile, Over spent Ni@S2-T catalyst, hardly any coke was found after
the prolonged test, which indicated the remarkable anti-coking ability
of Ni@S2-T. Thanks to the unique two-step synthetic processes, the
confinement effect of the silicalite-2 shell and stronger metal-support
interaction causing by the formation of Ni phyllosilicate were regarded
as the main reasons for superb catalytic performances.