posted on 2020-04-01, 11:36authored byLingzhen Zeng, Yongke Wang, Zhe Li, Yang Song, Jingzheng Zhang, Jing Wang, Xuefeng He, Cheng Wang, Wenbin Lin
We report the preparation
of porous hydrous zirconia by treatment
of zirconium-based metal–organic framework (MOF) UiO-66 with
a strong base. Microporosity of the original MOF was partially retained
in the resultant porous hydrous zirconia. NiII centers
were then adsorbed onto the OH-rich hydrous zirconia and in situ converted
to highly dispersed Ni0 for CO2 hydrogenation
to CH4. The activated catalyst after an induction period
showed a turnover frequency of 345 h–1 or a space–time
yield of 5851 mmol·gNi–1·h–1 with a CH4 selectivity of over 99%. The
catalyst was tested for 100 h on stream, showing only a 4% decrease
in activity, and was found to convert atmospheric CO2 to
CH4 via CO2 collection through Na2CO3/NaHCO3 cycling. Thermal decomposition of
NaHCO3 released CO2 for hydrogenation to CH4, and the resultant Na2CO3 absorbed
CO2 from air to form NaHCO3. This work highlights
the opportunity in using MOFs as precursors to prepare highly porous
metal oxide/hydroxide supports for solid–gas phase catalysis.